I personally feel Vladimir is among the trickiest of Champions to play well. His abilities are powerful and, but because his abilities cost health to cast, casting too wildly can make it quite easy to kill him. In this build, I focus on building a high AP Vladimir to cause serious damage.

Because Vlad deals magic damage, Magic Pen will make those attacks hurt even more. Health/Level will give both Health and AP and the AP/Level Glyphs and Quints will give both AP and Health, all thanks to his Passive.

Get Improved Exhaust and Magic Pen in Offensive, then 21 in Utility. As Vlad doesn't have Mana, don't get any Masteries that affect Mana, allowing him to get bonuses for Experience Gained, Monster Buffs etc.

The items listed allow give Vlad not only a lot of AP but also some survivability. First, start out with Boots of Speed and 3 Health Potions. Because Transfusion won't give you that much Health in the beginning, you need the Health Potions to stay in your lane. Also, the Boots will make getting in and out to score a Transfusion hit on an enemy much easier. Next, get the Boots of Swiftness and a Hextech Revolver for the added Spell Vamp. Next the Mejai's Soulstealer to start building stacks when you get kills. Finish off the Hextech Gunblade then get a Rabadon's Deathcap to boost your AP. Next, a Rylai's Crystal Scepter. This item is perfect for Vlad because it gives both AP and Health (and both give the opposite in return thanks to his awesome Passive) and it slows targets hit by your spells. Finish off by getting a Zhonya's Hourglass to give more AP, some Armor and the ability to go into stasis.

A quick word about the Soulstealer. At a full 20 stacks, this item gives 180 AP. With the Rabadon's Deathcap Passive bonus, this is then boosted to 234. In comparison, a second Rabadon's Deathcap will give 202 AP. The Soulstealer also gives 15% Cooldown Reduction. And it only costs 1235 gold. A soul-stacked Vlad can carry a team. Never underestimate this item. But if you're having issues keeping up the stacks, sell it for an Abyssal Scepter. It gives AP, Magic Resist and reduces Magic Resist of nearby Champions, making them even more vulnerable when near you.

If you haven't yet figured it out, Vlad's Passive gives him AP for getting bonus Health and Health for getting Bonus AP. However, the bonuses don't stack with themselves.

Transfusion is your best friend as Vlad. It has no cost, does immediate damage (making it a great last hit move) and heals him for a quarter of the damage done. Let's you survive longer than the enemies and is a great harassing tool.

Sanguine Pool is a great offensive and defensive move. Use it to slow enemies down that are running away or to run away from attacking enemies. However, it takes out 20% of Vlad's current Health, so always use Transfusion a few times after coming back up.

Tides of Blood deals damage to all enemies within the range of Vlad. This makes it easy to farm a large crowd of minions for gold. Also, it gives a bonus to Tides of Blood (max of four stacks), each one increasing the damage of each subsequent use by 25% while also increasing the Health cost by 50%.

Hemoplague is a great initiation to a team fight/1v1. It causes enemies to take increased damage for it's duration then causes damage again after it runs out. This costs 15% of Vlad's current health. Obviously, using it at the start of the fight will make your allies to more damage to them too.

When entering a fight, I like to use this combo:

R>Q>E>W>Q>E

I chose Flash and Ignite for various reasons. Flash for tricky escapes and getting closer to finish off foes. Ignite for added damage and to finish off those who barely are surviving.

If you took mid in the beginning, check the sides for an occasional team gank. Hemoplague makes it very easy to kill enemies both early and late game with it's damage increase effect.

Vlad is not an initiator to the team fights. However, you need to use a Hemoplague early in one to make it easier for your team. After you use it, target the high damage enemies with your other abilities and try to drop them. But do not stray to far from your team. If you chase after the one running away, you might kill them. If you frighten off the squishies on their team to a point where killing them would involve a lengthy chase, just focus on the tanks or anyone who has yet to run away. Sometimes, someone brave might even return just for a bit to try and save them.