Well, this is my first build. Warwick is a jungler so he would usually start in the jungle and then gank a lane.

pros: lifesteal ensures higher survival rate as you will heal per atk
cons: low mana, if he runs low on mana his abilities will be useless

Take flash because it is the most useful spell; it will save u and be a tool for chasing

Take smite, you're a jungler, smite will do lots of damage to creeps to save time and u will take less damage

I take dps fighters runes because it will make you stronger so you will deal more damage when you gank lanes, when ganking, damage counts the most. my quintessences are defensive because although damage is important, there's no point in having them if you're gonna die the moment you go in.

like I've stated in the runes, you need damage so go for 21 offense, no more, no less. I've taken into account that warwick needs mana in early game so i went for the extra mana. I also placed 6 points in defense to add survivability and you will be able to deal extra damage to creeps with tough skin.

Warwick benefits greatly with lifesteal, additional lifestyle to him will make him almost impossible to fight one on one,this will promise some kills as they probably won't know you had so much lifesteal. It will make you even stronger than a fed master yi. Madred's blood razor will an on hit item as well as black cleaver, these on hit effects will stack when you use your ultimate.

When warwick is getting the blue buff in early game, he will need something to heal him, so go for hungering strike as it will sustain your health long enough for you to kill it. Also go for hunters call, it will make you attack quicker, making you heal quicker. Blood scent will make you stronger when chasing enemies and ganking, but try to avoid going to the lane before you're sure you can take the kill, when the sign appears above their head, they'll retreat. (if they're not noobs)Infinite duress is a double edged blade, if not used right, you'll trap yourself in the turret's range and you will probably die. If you trap them in your turret's range, they will die.

Start off by heading to the wolves, kill them then tell your team's tank to leash the golem. Attack it,when it is a little more than half health, use smite, it will quickly end the golem's life. Head to whichever lane is having trouble, by now you should be at least lv2,use hunter's call and gank, if it is successful, go kill the wraiths and golems (the ones without the buff), if it is unsuccessful and he gets away, lane a little bit, then kill the other creeps. Remember to farm and continue doing this.

During the beginning of mid game, go for the red and blue buff, if it is taken, go to the other team's red buff, but make sure nobody is MIA. When you get the buff get out of there immediately. If they're MIA now and they weren't before, run straight to your base and heal. By now, you should have gotten your ultimate, it will help you greatly as you continuously gank. If a team fight breaks out, DON'T gank. follow the rest of your team and target the strongest damage dealer. Remember to get buffs as often as possible, but make sure the enemies not MIA.

Now that you're in late game, forget about creeps, only get the red buff. get the blue buff only if you really need it. Just push, gank, and kill. No more jungling.

If your up against a fed tryndamere and you can't kill him,get a thornmail, if you're up against a fed mage, get a banshee's veil.

Remember that a kill is usually not worth dieing for, but if the enemy is on a killing spree or something, than it is worth dieing for, remember that if it's just a guy that's just trolling around or playing normally, don't die to kill them. When you're dead, you're doing nothing, not jungling, not pushing, not killing, you're just dead.

Well, that's about it for my first build. hope you learned how to play warwick.