In Pokemon White I have a Golurk that I want to EV train?

HP/Def/Sp.Def with emphasis on Def/Sp.Def. If you wanted to help Golurk's SPD, you would have to devote almost all your EV training to SPD since it's pretty low to begin with, unless you got one with a jolly nature and only taught it physical moves (as it's Sp.Atk is pretty low as well).