This is just a basic Warwick build that can help many peopel that are new to him. Dot Warwick is easy to play and is a great addition to team fights.
Runes and masteries are jsut basic AD carry, feel free to change up on those.

Start at blue. Your Q and W will burn mana fast. After blue make your normal route through the jungle.
*Poke around in the enemy's jungle, but be careful. If you're lucky you'll find them in a vulnerable state.. but mostly jungle stealing is fun.
*Try to get a good leash on blue so you can save your smite for red. This will help you quicky proceed to red without waiting for smite.

A Warwick ult is quite lovely for starting a team fight. This build is a squishy killer. Ulting and taking out their carry is vital and one of the benefits of this build.

Sorry that I did not go into much detail. This is my first build guide and I'm sure no one reads this part anyway.