After playing a lot on Solo Top Role in both normal and ranked games i realised that Shyvana tends to be one of the strongest Solo Top Champions that is really difficult to counter-pick and outzone her. Even if you fall behind your opponent Shyvana is a very durable champion and not wise to turret-dive her. Easy to play champion without anything special to point out that early.
Note: That guide is not an "Anti- Tryndamere" or "Anti- Garen" style guide but it will give you many ideas on Shyvana playstyle and what you'll need to be a positive force for your team.

Pros

+Easy-escaping gangs in lane
+High mobility
+Passively high Armor/M.res
+Super strong 1v1
+Can escape gangs with ultimate

Cons

-If Burnout used early the duration is low
-Hard to land Flame Breath in human form
-No CC

It is most common that in Top Lane you are facing another meelee AD Champion. So i consider that Flat Armor Seals are the best choice for trading damage with your opponent. For Glyphes i recommend Flat Magic Resist that are totally usefull both in lane (Since many AD champions also have magic damage skills like shyvana does) but also when the enemy jungler Attacks you, Addionaly Flat Magic Resist is usefull in TeamFights. For Marks and Quintessences i use Armor penetration, Shyvana is an AD champion so Armor Pen. is the best option to melt down your opponents.

In Short:
Greater Mark of Desolation: These runes will give you a huge boost in damage. These runes are basically the best runes for ad champions, especially early game.

Greater Seal of Armor: The armor you gain from these runes is very huge early game, this will help you stay longer on your lane and it will help you ALOT with jungling.

Greater Glyph of Magic Resist: These runes will give you that nice magic resistance from early on.

Greater Quintessence of Desolation: Just like the marks, these runes give you a huge boost in damage.

My masteries are 9/21/0 focusing on Lane sustain and Damage Trading. Focusing on Defence Tree provides the best Lane sustain and also the tanking ability needed to either initiate or guard your carries. As mentioned above most times you have to face an AD opponent so u need the armor from the mastery tree. Also max HP is always usefull. It is very common that you trade damage in TOP lane all the time so you need HP regen provided in masteries. Shyvana gets a lot of speed from Burnout (W) but she doesnt have any slow effect so Initiator movement speed helps you chase down your enemy. And of course damage reduction and max HP are usefull.
Getting the AD and the Armor Pen. in offence tree is enough to make you a dangerous opponent, you dont really need any other mastery deeper in the offence tree.

I open up with Boots and Health Potion x3 most of the times, alternative i buy Cloth Armor Health Potion x5 if the enemy is really strong AD damage dealer like Garen. 1st item build i consider to be Wringle's Lantern cause of the Lifesteal/Armor/Damage it provides makes trading damage easier and also regenerate HP from killing minions, additionaly it helps you if you want to push a lane fast or killing Dragon/Baron. Then i move up to Phage for Max Hp and the chance for Slow Effect since Shyvana doesnt have any CC by her own. Totally usefull when chasing down an enemy. Next i build Witch's End cause of the attack speed bonus and magic damage on hit and some M.resist too. That item gives you great damage output and durability. At that point Shyvana can trade damage with almost every champion on the game and win (if not win everyone). Later comes Frozen Mallet for more HP and always slowing down enemies on every hit, on dragon form Twin Bite (Q) hits all enemies in front of you applying on-hit effects such as Witch's End and Frozen Mallet. I consider building Atmas Impaler next but i found out that a Warden's Mail and the Randuin's Omen is much more effective cause of its massive Armor bonus some max HP and the really strong anti-AD passive reducing att.speed of enemies that hit you. Then a Guardian Angel is a good buy for more Armor and M.Res and the revive passive.

Shyvana is a very mobile and strong champion. Leveling up Burnout (W) lets you chase or outrun any opponent. When Auto-Attacking Burnout's duration is extended so make sure that when you activate it you will do some Auto-Attacks. I suggest activating the skill by the time you are already in melee range from you enemy. Also if you activate it earlier it may damage minions and push you lane. On Dragon form Burnout schorches the ground and leaves a trail of fire that keeps damaging your enemies.

Twin Bite (Q) deals a lot of Physical Damage and its cooldown is getting lower for every Auto-Attack you deal. Also it refreshes you Auto-Attack timer so try to activate it after landing a hit so you can attack once more for free. On dragon form Twin Bite hits all enemies in front of you.

Flame Breath sends out a short range skill shot that damages a single enemy and reduces its armor for 15%. If landed on enemy champion it will really turn the tide on your favor but it's a hard skill to deliver. On Dragon form it damages and reduces the armor of all enemies in front of you.

Dragon's Descent (ultimate) it passively gives you Armor and Magic resist.
When activated those bonuses are doubled and makes all you skills have AoE damage. Also damages and knocking back enemies on the path of flight. Dont be afraid to turn on dragon form and fight with anyone!
This picture shows most of the walls that Shyvana can easily fly over with her Dragon's Descent activation.By mpou21 at 2012-04-08

Let's talk about farming.. What is farming? What can you do with farming? What will you achieve by farming? Well it's simple: It's almost the most IMPORTANT thing in this game to do, especially for Shyvana. Farming is also known as last hitting the minions, this means whenever you do the last hit on a minion and you kill it you will receive the gold from it. Doing this on every minions can give you loads and loads of gold without having to kill anyone at all. This is very important on Shyvana, she needs as much minions as possible (that's why she has to solo lane or junge). The best way to do this on Shyvana depends on what enemy you have. With solo laners like Garen or Trundle or almost every close combat fighter you can farm pretty easy, you don't have to tower hug to much. With solo laners like Yorick or Urgot you should wait till he pushes their minions to your tower so you can farm easily because long ranged harass champions can rape you without to much effort.

Last hitting under the tower:

Combat minion: 2 turret shots then 1 auto attack.
Ranged minion: 1 auto attack, 1 turret shot and then 1 auto attack.
Tank minion: Not really sure, just make sure you'll last hit this minions, it gives the most gold. This minions also takes 50% less damage from turrets which makes it easier for you to last hit it.


If your getting outzoned on your lane, you should call your jungler for help or you wont be to strong mid/late game.

When laning in top if you are on blue side means that the enemy jungler can only jump you from the river or less common from the bushes. This photo shows safes zones and where is best to farm minions.By mpou21 at 2012-04-08 By laning at that point u have space to farm all minions and not getting denied in your turret but also being safe from gangs. On top of that your jungler has space to gang your enemy!
a basic warding spot is that one. Building Wriggle's Lantern gives you a free ward so that bush will always be warded!By mpou21 at 2012-04-08
If your lane is pushed cause of Burnout AoE damage that hurts minions then you'll have to ward the tri-bush also.By mpou21 at 2012-04-08

Whenever im winning lane a lot (meaning im far ahead in gold farm) and my enemy buys ward to ward the river (mostly) i buy a Vision Ward to destroy his ward and make him feel helpless and unsafe.
Note: Placing the Vision Ward inside the bush allows you to see all enemy wards inside and outside the bush. So placing the Vision Ward outeside the bush you will not be able to destroy the enemy ward inside the bush.By mpou21 at 2012-04-08

~Solo Laners~
Yorick:
Yorick
Skills:
Unholy Covenant Omen of War Omen of Pestilence Omen of Famine Omen of Death
Difficulty to play against:
Hard!

Advantages over you:
* Can harass very good from a nice distance.
* Has huge lifesteal if Omen of Famine gets maxed out first.
* Has a constant slow which can be used on you when you're getting ganked.
* Has pretty low mana cost which makes him very annoying to play against.

How to counter Yorick:
* Try to keep a good distance between both of you or he can easily harass you without losing anything at all.
* If he maxes ]]Omen of Famine]] you shouldn't try to harass him, you will lose your health because he can just cast this spell and heal his health back. If he maxes Omen of Pestilence you can actually harass him, but be sure you are atleast level 4 and be sure to hit a pretty big chunk of health away or it wont effect him to much.
* If you are trying to take down Yorick, get your jungler to help. This gives you a much better chance to get him down instead of you not killing him which results in wasting health.
* Try to focus Yorick his minions down, this will help you keeping your health and this will heal him less (if Omen of Famine is casted). This will also decrease his damage / tankyness since his passive will get deactived if his minions die.
* Your AoE damage from Burnout can kill his minions fast
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Garen:
Garen

Skills:
Perseverance Decisive Strike Courage Judgment Demacian Justice
Difficulty to play against:
Hard!

Advantages over you:
* Has huge health regeneration when not in combat because of Perseverance.
* Has a long silence which can result in dead.
* Has an ulti which hits very hard when you are low on health, this can be used to finish you off very easily.

How to counter Garen:
* When Garen tries to hit you with his desicive strike, cast Burnout to start trading with him or run away (silence still remains though).
* If you are about to harass him, make sure you hit him pretty hard or he'll just regenerate his health back in a few seconds.
* If garen castes Courage, don't waste your spells on him untill this spell deactivates. When Courage is activated he blocks alot of damage from your auto attacks and spells.
* If Garen is using Judgment, I would suggest to activate Burnout and start hitting him with auto-attacks. Your Burnout lasts longer than his Judgment and also you auto-attack!
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Nasus:
Nasus
Skills:
Soul Eater Siphoning Strike Wither Spirit Fire Fury of the Sands
Difficulty to play against:
Medium!

Advantages over you:
* Nasus has a lifesteal passive which makes it hard to harass him.
* Has a really huge movement/attack speed debuff which makes it really easy for him to get you.
* Has an armor debuff
* Can have alot of damage by killing minions because of his Siphoning Strike passive.
* His ultimate increases his ad/health alot which makes 1v1 after level 6 almost impossible.

How to counter Nasus:
* When nasus casted Wither on you, try to run away until its almost over and suprise him with a counter attack.
* Try to avoid standing in Spirit Fire when having a fight with Nasus.
* Nasus has alot of lifesteal so try to avoid hitting him a litle bit and try to hit alot at once.
* If he casted his ultimate try to avoid fighting him untill his ultimate is over, this will give you more chance to kill him instead of him killing you.
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Mordekaiser:
Mordekaiser

Skills:
Iron Man Mace of Spades Creeping Death Siphon of Destruction[[children of the gravve
Difficulty to play against:
Medium!

Advantages over you:
* Has an overshield which can be pretty hard to get trough.
* Every skill is AOE damage except for his ultimate.
* Can harass really easy from a nice distance.
* Can farm minions in no-time with Mace of Spades and Siphon of Destruction.
* Can clone you if killed by Children of the Grave which makes killing turrets easy for him.

How to counter Mordekaiser:
* Mordekaiser is fairly predictable. Whenever he moves forwards towards you and your minions, just move away. You don't want to take a Siphon of Destruction, as well as the fact that he get's double the shield if he hits champions.
* When his overshield is gone, try to harass him. Most Mordekaiser players have 500 health at the beginning with a litle bit resistance which makes it easy for you to take chunks of health away from him. Also, when he killed your minion wave it's also a good moment to harass him, he can't keep his overshield high without him hitting your minions.
* Mordekaiser is a cooldown dependant champion, take advantage of this, harass him when he just casted his spells.
* Try to keep your health above 50%. A good Mordekaiser will easily tower dive you if you are low on health which results in an easy kill for him, especially when played versus a Mordekaiser with Heal.
* Mordekaiser is fairly easy to gank if he's pushed up. He has no CC, so as long as your jungler has a snare or taunt ( Maokai, Rammus), or even any type of CC, he will be in trouble. He also has a hard time assisting his jungler to gank you, as when he approaches, you can just back away to avoid damage, and he has no CC.
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Warwick:
Warwick
Skills:
Eternal Thirst Hungering Strike Hunters Call Blood Scent Infinite Duress
Difficulty to play against:
Hard!

Advantages over you:
* He has huge lifesteal because of his passive and Hungering Strike
* 1vs1 battles is mostly a win for Warwick.
* Has alot of movement when enemy lower then 50% health.
* Has long ranged supress which procs on-hit effects just like Twin Bite.
* Has an AOE attack speed buff.

How to counter Warwick:
* Try to avoid getting in a 1v1 battle with him, in most cases he will win because of his huge lifesteal.
* A good item to counter Warwick is a Null-Magic Mantle, this will reduce the damage of his passive, his Hungering Strike and Infinite Duress alot.
* Don't try to tower dive Warwick even if he has low health. He might suprise you by casting Hungering Strike on you which results in huge lifesteal for him and huge damage for you.
* Blood Scent gives Warwick a huge movement speed boost whenever you are below 50% health, try to avoid getting this low by using Health Potion and tower hugging or he'll cast Infinite Duress without any problems.
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Sion:
Sion
Skills:
Feel No Pain Cryptic Gaze Death's Caress Enrage Cannibalism
Difficulty to play against:
Easy-Medium!

Advantages over you:
* Has a shield which blocks alot of damage rather then blocking on auto attack if he goes AP.
* Has a long stun.
* Feel No Pain reduces your damage auto attack damage a litle bit.
* Is the ultimate lifesteal champion if he goes AD

How to counter Sion:
* AD Sion: Wait for him to stun you and activate your Burnout right away. That will allow you to counter his damage before the stun fades and you are capable of making him pay. Avoid fighting him while his ult is on, if he has enough attack speed you won't be able to finish him and he will ending up killing you. But, if your choice of summoner spells are Ignite and Flash, you can Ignite him to cut half his lifesteal/health regen and you can finish him with your abilities. No hits = no life steal = dead.
* AP Sion: Just a pain in the ***. His stun and shield hurts like hell, but really only from level 5 ahead. The only way to counter him is to throw him into long fight, AP Sion makes it a hit and run game which means short fights will give him an advantage and long fights will give him a disadvantage.
* AP Sion: Play agressive from the start. He will likely stun you and run near you to blast his shield (which is his only way to soak damage during lane phase). When he does that, he will push the lane (nice to us!) and lose his defenses for some seconds. Jump on him and harass the **** out of him. AP Sion can't sustain in lane like AD Sion, he keeps himself fighting by bringing the enemies into low health and zoning them. That is just what you don't want to happen, for that you have to dominate him, or you will be dominated.
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Irelia:
Irelia

Skills:
Ionian Fervor Bladesurge Hiten Style Equilibrium Strike transcedent blades

Difficulty to play against:
High


Advantages over you:
* Passive CC duration reduction ( Shyvana doesnt have any cc but your jungler will do)
* Can jump straight on your face with Bladesurge, also can escape gangs by jumping into your minions
* Passive HP regen on Auto-Attacks and with ulty
* True damage with Hiten Style on auto-attacks
* Extremely high slow
* Equilibrium Strike can stun you if your HP is higher than Irelia

How to counter Irelia:
* Shyvana is faster and can easily go in and land some auto-attacks and Burnout damage and the go out of battle
* Irelia is a mana source user, when she's low on mana feel free to trade with her
* Most of Irelia damage comes from Hiten Style true damage, while activated try to kite her and when it ends go right on her.
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Cho'gath:
Cho'Gath

Skills:
Carnivore Rupture Feral Scream Vorpal Spikes Feast

Difficulty to play against:
Medium!

Advantages over you:
* Passive Hp regen when last-hitting minions
* Has 2 CC slow and silence
* High Hp after lvl 6
* Pretty durable
* True damage with his ult

How to counter Cho'Gath:
* He cannot trade auto-attacks with Shyvana
* You can easily use Burnout to dodge his Rupture and chase him
* He's mana depended

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Fiora:
Fiora

Skills:
Duelist Lunge Riposte Burst of Speed Blade Waltz

Difficulty to play against:
Medium!

Advantages over you:
*High Hp regen after hitting minions or champion.
*Can totally block damage from 1 auto-attack
*Passively high AD
*Untargetable during Blade Waltz

How to Counter Fiora:
*She has no escape skill. Her Burst of Speed doesnt give MS if she's not hitting.
*You can bait her Riposte that only lasts for 1.5s so you can attack her right after.
*She's an auto-attacker, if she gains advantage over you build armor boots instead of m.res
*when she activates her Burst of Speed try to kite her and attack her when it's over. Without it she's not strong.

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Gangplank:
Gangplank

Skills:
grog-soaked blade Parrrley Remove Scurvy Raise Morale Cannon Barrage

Difficulty to play against:
Medium!

Advantages over you:
*Passive slow on hits
*Can remove CC
*Range spam skill ( Parrrley)

How to counter Gangplank:
*Start with Cloth Armor and 5x Health Potion
*GP has to stop in order to cast Parrrley and Raise Morale use that for your advantage
*Many GP players cast their ult to assist their teammates. So when his ult is on cooldown feel free to attack him.
*Higher Armor and M.res

Shyvana is Super-strong on early and mid game. Late game is for carries :p
That doesnt mean that you can just kill everyone but if played well that can be done. Try to seize every opportunity that you may find you opponent a little off-guard to start damaging him. Not many enemies know how strong Burnout is cause they dont add the damage from your Auto-Attacks. Dont be afraid to initiate fight and fly towards the enemy carry. Shyvana has great damage and all AoE on dragon form!