PROS
-lots of sustain
-fair damage
-high movement (especially in team fights)
-life steal
-can NOT be counter jungled (unless you go red without checking the bush)
-Blade of the ruined kings + Mercury threads + someone low hp> 600 movement!
CONS
-useless till 6th (unless they are pushing)
-his escaping is based on 1 spell (and it doesn't work most of the times)
-watch out for Fiddlesticks!!! (fcking draining brainless... xD )

There are no jungle items because Warwick doesn't need any-he has both sustain and damage to cut through all monsters even while he is at low level!
You can choose between Black cleaver and GA and Warmog's armor to be your 6th item. Black cleaver works best for me because it ,combined with Wit's end and Warwick's ultimate and passive, stacks all 5 times dealing 700 damage and more on squishy champs. The rest of the build is pretty much health-based.

All in favor to the early fast jungle clearing and enormous damage while ganking. You can try putting Warwick in utility but..ermmm.. I don't like the bonuses. Utility sux in late game-it gives you less than nothing. Since build is tanky I don't waste my points on defence and put 21 points to offence tree.

All obvious-good runes for him all game round.

1. AD on marks-important for both damage and life steal
2. Armor on seals-easier job versus monsters, ad top and adc
3. AS on glyphs-good with his passive but you can try scaling magic resist in case of too much ap on their team ;) and...
4. Life steal on quints - healing more than 10 damage on hit on FIRST level
P.S. That's why I don't need no Hunters machete and stupid 5 hp pots - dagger ftw !

Q and W are the most important spells-therefore I don't waste much talents on mega movement that E provides. I take E every time before my ultimate because i need it only then to chase down a kill.

Warwick has 1 purpose:
to save his ultimate for ADC and only focuse him/her! (only Vayne can escape you but your Frozen mallet will bring her down)

His W is the BEST pushing spell in the game and really good boost for your ADC in TFs.

Ain't it simple :D ?

Magic trick:

Don't go red asap(about 3.00-3.05 minites of the game)-do golems 1st and as you reach level 3 you'll have 2 skill points on Q so no one will even think about invading your jungle (transfering 150 hp from 'em like a boss ;D )

Magic trick 2:

Wit's and with Warwick's passive (both maxed) deal 100-120 damage on hit (and Wawick hits fast - Huehuehue)