Warwick, a pretty good character to both lane or jungle with. He can stay in a lane for a long time and after he get's some lifesteal items, he is almost impossible to take off a lane. He can jungle very effectively because of his innate and hungering strike.

Pros: Good Survivability
Can regen at insane rates after hextech
Can Jungle easily
Quick attacker
Good Chaser
Can detect near dead enemies

Cons:
Not too tank
Can be ganked pretty easily
Not too good Early game

Ghost and Ignite = best combo. With Ghost, you can both kill and run away with it. Warwick is a very good chaser and this spell only enhances it. Ignite is also very good because if a person is on very low hp, chucking an ignite at them means death to them.

When you look at my guide, you'll think "Why Doran's first when they'res others?" I use it first because it gives basic lifesteal and some life drain. Next item you'll want is a vampiric scepter to increase your lifesteal, which enhances your laning ability. After that, you'll want some good ol' boots. Beserker's fulfill both movement speed and some attack speed. Next is a black cleaver, a must. It stacks with your ulti and it allows you to take down the enemy very quickly. After that is a phantom's, a very good item for all attack speed characters. It gives a lot of attack speed and also the ability to chase better. The movement speed is invaluable against enemies with ghost as, coupled with your ghost makes you very fast. Bloodthirster, an essential item for Warwick. The lifesteal from this is godlike and coupled with your innate, makes you regen in 6 hits. It gives more damage and lifesteal then any other item when fully stacked and makes you op. After this, it's an infinity's edge. Probably the strongest item in the game, after a stacked bloodthirster. It makes you a warwick to be feared and with the crit rate you have already, you'll be hitting crits once every 3 shots. After all these items, your pretty OP already and to finish up, you'll want a 2nd Phantoms. This will make you literally impossible to run from. Coupled with the crit rate from this item, it's basically crit every strike. This is my item build which has done good on me with every game, though some people may not like it.