when playing as warwick what you want to be able to do is be able to initiate but stay alive with your q (thus all the ability power) and because of your attack speed and life steal you can gain life just by attacking normally or using your W.
so basically your ult is used to go in there and stun there weakest player thus making him the point of attention. That usually takes like 1second because that person usually has really ****ty life. This build is great because if used properly you can stay alive for very long and your q does LOTS of damage.
depending on wether its a 3v3 or a 5v5 depends if you get hungering strike first or blood scent...if your in a 3v3 i would suggest blood scent first just for the opening gank, but if its a 5v5 go with hungering strike so you dont have to use your pots in unnecessary situations.