This is how I am currently playing WW, my Runes and Masteries are exactly what you see on this guide. My build order for items is always the same up to the first Bloodthirster. If the enemy team has no tanks and maybe a lot of AP then I will not make a Black Cleaver I will then make something to counter that like maybe a Wit's End. If my team has a lot of Attack Dammage I will make Stark's Fervor and pass on the Black Cleaver some times just to help them out "since I'm such a nice guy and all". After that I go back to my second Bloodthirster. If I wind up making the second Bloodthirster it's already a long game and probably time for some defense so Warmog's, Randuin's Omen or a Guardian Angel.
For the Jungle I kind of use a different approach to it, I start with One Cloth Arm and Five H Pots. Double Golems, Wraiths, Dogs, Blue Buff enemy teams Red Buff then I recall if I can not set up a gank. Second time out Dragon, clear and set up a gank. I usually don't want to go back to much so I will help push a turret and go jungle a third time as well before going back if I can.
The way I have this set up, I never fear a lot of AP my blue MR Runes help, I don't mind ganking on tanks as the red ARM Pen Runes help too. Yellow AS Runes for a quick Jungler that can keep its health up. Since WW is not a tank, I don't try to tank with him but that last one defensive item is almost a must if the game goes on that long you're going to need it.