I started playing league one year ago and I main Warwick. I was Bronze III and in 8 months I climbed the ladder to Platinum 4 with Warwick. If you want to know how to do the same read the rest of the guide. I have actually a 66,67% win rate on around 170 games on Warwick.

During this guide, I will explain to you guys what are my runes, my masteries, my build and much more.

Pros:
-Gap Closer
-Insane Movement Speed Buff
-Free Assists with his W
-Good Tower Pusher with his W
-Very Good Sustain with his passive
-Easy early dragons with his sustain
-Good Chasing Potential
-Q Scales % Max health
-Insane level 6 ganks
-Good Catch potential

Cons:
-Completly Countered by Qss and Cleanse
-Bad Ganks before level 6
-Tough to play in top Elo ( Low plat and Diamond )
-Needs his ultimate to be useful
-Can be easily kited without his ultimate

My personal choices
-9 AD Marks
-9 Armor Seals
-9 Scaling MR
-3 A.S. Quints

Other Possible Options

-9 Hybrid Penetration Marks
-9 MR, 9 Scaling CDR or 9 flat CDR
-9 AD Quints

My personal choice
Leveling Order: R-W-Q-E

Why not R-Q-W-E or R-Q-E-W?
Simply because the maxed Q costs a lot of mana and without blue buff your sustain will be reduced. Also the W max makes it faster to clean your jungle. To finish, maxing E is just horrible.

I guess there's not a lot of choices.

-Smite is the core of every jungler.
Choose between
-Flash (awesome flash ultimate combo)
-Ghost (nice chasing potential and pre-6 ganks)

Both are very good but personally I prefer flash just because it's better defensively.

Warwick is a late game monster. He NEEDS gold. Tax whatever you want and farm the lanes when your teammates aren't there. If you are under 100 c.s. at 20 minutes... There's a problem. Sit in your jungle until 8 minutes in the game where your will have enough gold (normally) to buy your devourer. During these 8 minutes, you shouldn't take scuttlers, dragons or even gank because it will (most of the time) be useless. After that, you should think more seriously about taking scuttlers and dragons because of the stacks that they give. Also, don't listen to these kind of comments from your mates like ''Gank me your level 6''. It's completly stupid to gank level 6 because you normally don't have devourer level 6 so that means that your ultimate will deal almost no damage. But if it's a free kill take it even without devourer because it will give you gold and THAT'S WHAT YOU WANT!

Basically as Warwick, you want to get your core items (Dev.,Wit's,Guinsoos) as fast as possible. As soon as your devourer is sated, you sit either top or bot and you begin to farm lanes and alternate with the jungle to have the most experience as you can. If there's somebody who comes to defend the lane, don't waste your time make sure it's safe though, fight him unless he has more than 5 kills above yours because Warwick can pretty much 1v1 anybody.
(Read the matchups for more details)

This is one of my strats in my solo queue games. This is a technique that only works if you are relatively fed. If you have Wit's end, Sated devourer, guinsoos and hextech you can solo baron fast enough. Just wait until the dragon timer is up and just go sneak it by bringing a pink ward and you can shout ''Freelo''.