Size what ever*whatever, turn backface cull off, turn show overlapes off, select under colors or something like that constant then choose a black.
Now hit pic object, select the object you unwrapped. It pops up in a new window, if you like it save it. If not close it piss round with the options again the pick object again.
Now paint it.
Once painted, select your unwrapped object, press m select bitmap from somewhere , find your map, hit aplly to selection button then show in window button. Done.
Sorry if this is a bit off but i wrote this of the top of my head, didnt have max open