Draven is an EXTREMELY hard to play Champion. Follow this guide, and you can soon be demolishing, too. Sell Doran's blade to buy Madred's Bloodrazer, btw.
To start off, but Doran's blade. This will leave you with nooo money, but you gain it back quickly. Next, I go with the boots of speed, to later be upgraded to Berserker's Greaves.
Then I get the B. F. Sword, which I upgrade to The Bloodthirster. I buy another B. F. Sword, which is upgraded to The Black Cleaver. Then I get ANOTHER B. F. Sword, which is then upgraded to The Bloodthirster.
Pros / Cons
Pros: Draven is extremely OP. His Ult has unlimited range. He is a AD ranged carry
Cons: He is hella difficult to master