Vladimir is a very simple and over-powered champ once you know how to use him. Once you get down how he works, it will be a simple task to dominate anyone out of mid. Vlad is played best when he is built as an AP-Tank Hybrid since he scales off HP and AP. His passive gives him bonus HP per AP he has and bonus AP per HP he has. Building strait HP for the bonus AP is not recommended as it gives a substantially lower bonus.

As with most AP champs, you want to max out your AP runes with Vlad. Building HP runes with Vlad is again not recommended as it has a really low scale rate with his passive. Maxing out your AP is not only a good idea for Vlad, but will allow you to play many other AP champs at their best.

With your Masteries you want to max out all of you AP stats in offense; reaching Executioner. Next you want to put your remaining points into some HP Masteries as this will give Vlad extra AP off the start because of his passive.

Building Vlad, you want to start off with an Amplifying Tome and rush your Will of the Ancients as fast as possible; this is Vlad's core item and will allow you to out-lane anyone you're up against while giving him 80 AP. After boots, you should get a Giants Belt to give yourself more HP so that you can last longer and get additional AP from Vlad's passive. Next you should rush Rabidon's Deathcap to give yourself a giant boost in AP. Now you need Rylai's Crystal Scepter to not only give you AP and HP, but to slow your targets as well. Since Vlad hits multiple targets with many of his spells, Rylai's makes him great in team fights. The next items are optional, but I get 2 War Mog's to boost his hp to over 6000, making him a ridiculous tank and a beast in team fights.

Your Q (Transfusion) is your sustain in your lane, and should be taken first and maxed first.
Transfusion will heal you a great amount after you get Will of the Ancients.
Your W (Sanguine Pool) is your escape route and your slow, pick it up at lvl 4 and max last
Your pool can also be used as a way to not be hit while you wait for your cooldowns.
Your E (Tides of Blood) is your combo spell, use it before your Q to stack some massive damage,
this spell will also heal you with your Will of the Ancients, so using it in big groups
of minions or team fights is a great strategy.
Your R (Hemoplague) is basically your multi-hit ignite, doing a huge amount of damage late game.
this is the spell to start with in a gank or team fight, as it will make all of your
other spells do more damage, and will finish your opponents off if they get away.

Ignite: Getting Ignite with Vlad is great because it stacks with all of his other burst and
damage over time spells, if you hit them with this and all of his other spells, they'll
be dead before they even realize it.
Exhaust: Being that Vlad is a great team fighter, it makes sense to have this spell to counter
any strong opponent in the group. And as a mid it can ensure a quick mid kill to gain
levels and gold over the other player. Exhaust can also be used as another slow in
Vlad's arsenal.

-Vlad is a great solo and team fighter
-Will of the ancients is the key to his build
-Vlad is a great tank and Damage out-put
-Use your E before your Q
-Pool to get away in a rough spot or being focused
-Vlad is best in teamfights