With Warwick, start near the Blue buff. Make sure to have your Cloth Armour and 3 Health potions. Blue buff will spawn at 1:50, while attacking, keep on the lookout for gankers and your health, be sure to use one Health Potion and no more than that. Make your way through Wolfs, Banshees, Red buff ( do not use any more potions besides that one of blue buff, if spawned on Purple team, then this won't work and use potions as you like. ) and Goloms. Make your way over to the enemies jungle and take their blue buff because yours should be low at this point, but your red still high. You should be level 4 at this point, make sure to have a good amount of health as well, and charge into Dragon using both your Health Potions you saved, and your skills. After achieving this, you should have enough to get Berserker's Greaves. Jungle or assist others and continue this build, and you should have no problem with it later on, major tank killer by the way.