Hello people,
I noticed that urgot isn't played a lot. But I really like him and I'm pretty good with him. So I asked why people don't play him and the most given answer was: "he's not good and hard to build." But I'm here te solve that. I hope you learn something from my guide (which is my first btw, so advice is welcome).
I followed the big lines of JhoiJhoi's guide and I'd like to thank her for her amazing guide on making guides.

Pro's

Con's

+ High amount of damage + Spammable poke + Doesn't need a lot of practice + Not hard to snowball with

- Ulti is hard to use/master

I would take this for the map presence it provides. Probably the best skill on top lane.

I would take this because Urgot doesn't have any escape mechanisms. This is very useful when being ganked or just to escape when you're in a disadvantage.

Ignite can be used to increase your already massive damage. Or when you're laning agianst a champ like Dr. Mundo or Warwick who relies on health regen or lifesteal.

The Greater Mark of Scaling Attack Damage are obviously necessary for the damage :).
The Greater Seal of Scaling Armor gives Urgot the surivability to deal his high damage.
I chose Greater Glyph of Cooldown Reduction so Urgot can spam his Acid Hunter even more often.
Since Urgot has an expensive build, I chose for Greater Quintessence of Gold.

Skill Explanation

Zaun-Touched Bolt Augmenter: Urgot's basic attacks reduce his targets' damage by 15% for 2.5 seconds.
This is very useful, because you will encounter a lot of AD champs in top lane.

Acid Hunter(Q): Urgot fires a missile toward the cursor that deals 10 / 40 / 70 / 100 / 130 (+85% of your total Attack Damage) physical damage. Missile-lock can be achieved by holding the cursor over a target afflicted by Noxian Corrosive Charge.
Use this skill to poke your enemy. It will also be your main damage source. Spam this between your basic attacks.

Terror Capacitor(W): Urgot charges up his terror capacitor to gain a shield that absorbs 80 / 130 / 180 / 230 / 280 (+80% of your total Ability Power) damage for 7 seconds. While the shield is active, Urgot's attacks and missiles slow targets by 20 / 25 / 30 / 35 / 40%.
This shield will not be very absorbing because you will not have a lot of AP in this build. However, it's usefull for slowing enemies who are chasing you are who are running away.

Noxian Corrosive Charge(E): Urgot launches a Corrosive Charge at a target location. Enemies afflicted by the charge have their armor reduced by 12 / 14 / 16 / 18 / 20% and take 75 / 120 / 165 / 210 / 255 (+60% of your bonus Attack Damage) physical damage over 5 seconds. Acid Hunter is able to missile-lock onto targets affected by Noxian Corrosive Charge.
This is a skill with some nice damage, but it's most useful for achieving the missile-lock on your Acid Hunter.

Hyper-Kinetic Position Reverser(R): Urgot targets an enemy champion and channels his Hyper-Kinetic Position Reverser for 1 second, swapping locations with his target afterward. His target is suppressed for the duration of the channel. Urgot gains 60 / 90 / 120 armor and magic resist for 5 seconds at the beginning of the channel, and his target is slowed by 40% for 3 seconds after being swapped.
This is Urgot's ulti. It's hard to use and not very useful in laning phase, but when teamfight start to occur it's pretty useful to pick out squishy targets and to provide yourself some defenses.

Ability Sequence Order

First I suggest to take 1 point in every ability. And later first max Acid Hunter, after that Noxian Corrosive Charge, and last Terror Capacitor. Of course you put a point in your ulti Hyper-Kinetic Position Reverser whenever possible. Terror Capacitor is maxed last because it scales with AP, which we will not buy, but point we take for the slow that it provides.

Berserker's Greaves: These boots are necessary for attacking faster, which is very useful for a champ that (partly) relies on his basic attacks like Urgot.

Trinity Force: This is a very useful item on Urgot. I gives good basic stats, but we take it most for it's passive Moonflair Spellblade. After every Acid Hunter Urgot's next basic will deal bonus damage. So if you fire an Acid Hunter every 2 seconds between your basic attacks, it will massively increase your damage.

Muramana: This item rocks on Urgot. It's charged very fast with his basic attacks and his Acid Hunter. And once it is a Muramana, you have to toggle it. When you do this, every basic attack and every Acid Hunter will deal increased damage.

Bloodthirster: We take this item for obvious reasons: it gives a huge amount of AD and a lot of Lifesteal.

Blade of the Ruined King: This item we take because of it's very useful stats. And it's passive is very useful too because you will often encounter a tank in top lane.

Black Cleaver: This item I also chose for it's good basic stats and it's armor penetration because Urgot's damage is physical.

In teamfights Urgot should try to pick out the enemy AD Carry or another squishy target with Hyper-Kinetic Position Reverser so your team can slay him and then the fight is already half won.
After you used your ulti, you should try to do as much damage as possible to the enemies with the highest damage. The best method for this is auto-attacking and firing Acid Hunter between your basic attacks.

As you should know, warding is vitally important to win a game. As top laner you should always try to keep Baron Nashor warded and you have to arrange whether you or your jungler wards your blue buff and the enemy red buff.
And if you see that the enemy jungler always takes the same route to gank you, you have to ward that route too of course.

I hope you will try this guide and leave a comment how it worked out for you. Advice or any questions are welcome.
Have fun

- Six66