Hello and welcome to my first guide on Mobafire.
I've attempted to be as concise as possible while offering all the necessary insight which provides effective use of Vladimir in the current meta. It's expected you understand the basics of counter-play/build.

This goes for all champions, but its even easier to forget when playing the walking health potion that is Vladimir: Never sit on too much gold.

ATTENTION: The bulk of the build information is included on the Items/Runes/Masteries/Matchup notes; These chapters might repeat some points mentioned in said notes but will mostly expand on what I feel is important in being successful with Vlad.

Vlad good

Sustain
AOE burst
Wave clear
Invulnerability

Vlad bad

No hard CC
High cool downs in early lane
Predictable plays

Farm safely. Try to freeze lane with last-hit autos, but don't be afraid to use skills to secure the CS.

This is key - If you don't maintain decent CS/minute for 1-6 you will have a rough time in the transition to mid game. Playing aggressive is fine and dandy (and easy on Vladimir) but its important to understand your damage output and the damage potential of your lane opponent. Most champions have predictable playstyle, and the meta for top is mainly melee - offering you an auto-attack harass advantage for nearly no risk. However any gap closer offers significant threat (Fiora, Riven, Irelia).

Again: Early game it's more important to secure farm than to establish harass dominance. With the prescribed starting stats you can outlast even the most annoying starts during lane.

Always take the opportunity to Q+E+auto when your opponent moves forward to grab melee minions. Basically anything you can get for free//take only light damage is worth, even if the damage you take is higher than what you put out. Forcing your opponent to either miss CS or use mana to trade is the goal in the lane. If you get dangerously low, play it safe and spell vamp on minions to get healthy.

Once your lane opponent is OOM or injured you can start being aggressive; Even when you're going against much higher base damages, you will notice the desperation in their play style.

Only very high sustain kits should force you into defensive play style: essentially you lose your advantage in trades if they can heal it too.

The last key point to highlight is the importance of keeping four stacks on your E all the time. Letting your stacks fall significantly cuts your trades and takes a while to restack without cool down reduction.
Using your E even when completely alone can become necessary; fear not, the health you get back even before your Hextech Revolver purchase is much more than the cost of the stacked Tides cost

If you have made it to level 7 without dying, then congrats: you've won lane. Your skills are approaching low cool downs even without CDR, making your sustain even more oppressive.

This phase of the game is more about counter play than anything: utilizing your TP to secure Dragon or turn an engagement bot or mid is the easiest way to contribute to your team. If your whole team is winning lane or reasonably farming, you can start to zone the enemy top laner and push your turret quick.

Ganks hurt. Wards are your friend. Obvious information here, but again: buy wards.

Vlad has a tendency to push waves with E and it can force you into vulnerable spots to keep farming.

The best strat at this point is to leave your opponent low but not to scare them completely off. Zone them from as much farm as possible, but make sure to always make getting your own minions the priority.
Securing a kill is nice, but even then most champs in the meta will be able to kill you while being 800+ gold behind. Additionaly a low health lane opponent will make the jungler weary of ganking, especially if they have unreliable CC. When the laner is too low to safely follow up, theres almost no contest, you just freely trade with the jungle and deny the gank.

Vlad with CDR is great at turning 2v1 engages, especially on skill shot champs. Using your pool to evade hard CC/massive damage is a great disengage - most people just fall off after you pool their pivotal skill, and the cooldowns of most hard CC offer a safe window to throw your spells relatively safely; all the while gaining health off any damage you do.

If you survive flawlessly on what they assume is a for-sure gank, the effect is Singed-like: they wont want to come waste their time chasing a pool of blood around top lane.

Vlad absorbs damage, plain and simple. Tower shots, skill shots, minion damage, whatever.

If they're low or OOM and you have an eye on the enemy jungle, Vlad is an amazing harass under turret. Taking a turret shot to land a Q when they're already low is worth every time - after the dangerous early game, now it's easy to shrug off the damage and heal it like nothing.

Ah, the teamfight phase.
It's time... to p-p-p-p-p-pool!

Your job is to be a frontline meat shield, plain and simple.
Your ult, against 90% of team comps, allows your team to engage on just about anything.
Its always advised to try and land your ultimate on 2+ squishies, and proceed to soak up damage while bursting the priority targets with your team. However if the enemy has an incredibly aggressive front line, sometimes they get cocky and shift slightly too far ahead of their carries: you can often ult the lone tanks and burst them down with your team, achieving a number advantage for fighting.

Generally speaking, ulting less than 2 people is bad and only advised when catching someone out or in skirmishes. Its usually hard to catch all five people with your ult, so look for opportunities to collapse on groups from behind/side to have the upperhand in positioning. Vlad can go HAM and have relatively little consequence due to the utility of his W (combined with the fact that most heavy nukes get used in the first few seconds of team fighting anyways).