Yeah, sup. I got bored and started playing Warwick a lot so I decided to make a guide.
This might help you, it might not.
Random note; How you play will affect your game way more than the items you have, so don't suck~
Yeah, that's a picture of Warwick, I'm being cliche and adding a picture of who i'm building.

More cliche stuff, woo!

Pros Easy to play Can jungle well Good CC Good ganker post-6 Doesn't need health pots etc.

SPACE

What cons? Derp Horrible mana regeneration, but you have blue buff so who cares. Bad ganks pre-6. Kind of slow. Uhh, other stuff I can't think of.

Yeah, you have these things, what a shock.

Passive: Eternal Thirst
What makes Warwick such a good jungler, and gives him quite a bit of survivability, nothing else to say.

Q: Hungering Strike
Another thing that makes Warwick a good jungler, does damage and heals himself, cool.
It's also ranged so take advantage of that, if you can, somehow.
Oh and the mana cost sucks.

W: Hunters Call
Attack Speed; good for pushing, healing yourself with your passive, buffing your team, etc.

E: Blood Scent
A run speed increase and you can see low health enemies near you if you're ******ed and keep it on before you're ready to gank, it kind of gives away that you're near.

R: Infinite Duress
Awesome ability for ganking, a suppress that does a lot of damage, heals for a lot and has good synergy with Madred's Bloodrazor
Except it's gay because it has a delay on the damage and healing it does.
Can lock down a carry, save a teammate, shred a tank, etc, it's good all around.

Smite You're a jungler, get it.
Flash This plus Infinite Duress, 'nuff said.
Ghost Not as good as Flash in my opinion, if for some odd reason you want it, take it.
Cleanse You probably shouldn't be in the position where you need to use this, plus if you get CCed during Infinite Duress and Cleanse it, it's not like you keep ulting, so it's not too great.

All other Summoner Spells should be left up to other roles to get.

Buy them, and don't complain that you're losing because someone else has them, you're gonna need them to jungle this way.

Greater Mark of Attack Speed Attack Speed for more sustain with your passive and damage in the jungle.

Greater Mark of Desolation
Armor Penetration, kinda self explanatory, only one because it gets you to exactly 12 ArP which is all jungle mobs have.

Greater Seal of Armor
Good survivability in jungle and in team fights, since you're an off-tank. Makes jungling so much easier.

Greater Glyph of Magic Resist
Good survivability outside of jungle and in team fights, since you're an off-tank.

Greater Quintessence of Desolation
Same as marks.

Other options:


Greater Glyph of Cooldown Reduction
Eh, this works, except I play Warwick a little tankier.

Greater Quintessence of Health
Health Quints, good on anyone even after the nerf, but I prefer ArP.
"But, you just said you play Warwick a little tankier"
Yeah, I did, but that's mid-late game, what is 78 health going to do mid-late game?

Greater Quintessence of Attack Speed
Same as marks.

We're not doing that in this guide, sorry, Lanewick~

All you have to do is get Madred's Bloodrazor. There, you're done.
No, but seriously.
After you get you're Madred's Bloodrazor, look at how you're doing, if you're doing good then get Bloodthirster, if not, counter the enemy team.

Look at the enemy team, who has the most kills? Who has the second most kills?
Counter the enemy team, if they have a lot of AP damage, get a Banshee's Veil
If they have a lot of AD damage, get a Sunfire Aegis, or a Thornmail

After about 150~ armor and magic resist, they start to lose their value.

Items not to get:
Frozen Mallet
You're a jungler, you should have red buff most of the game.

Frozen Heart
Leave it to a support/tank to get this item.

Aegis of the Legion
Same as Frozen Heart

Any AP, CDR, or Mana/Mana regeneration item.

That's all I can think of, lawl.

Buy them!
They're so powerful, I bet every time you go back to base you have at LEAST 75 gold, sometimes more.
Sometimes even a few hundred, in which case you can buy a few wards, or if they aren't needed at the moment, an elixer.

Don't just buy them after full build, they're incredibly powerful all game.

Ward placement: There's a ton of pictures out there, look for them.

Double Golems
Wraiths
Wolves
Blue
Recall
Red
Gank

Yeah, I know this was a short guide, I didn't have a lot of time, or patience. I did this out of boredom, so I guess this is kind of a beginner guide.
Maybe i'll add to this guide and keep it updated, maybe not.

Hatuhz gunna hayt.

Updated September 13, 2011. Changed runes, jungle route, cons, and masteries.