nice model! if you wanna make a skin for it the best program to get would be HLModel Viewer you can get it from the same place as milkshape and you can import the design of the skin. (remember has to be in 256 colours!)
to know where to color you have to skin map it. skin mapping isnt the easiest thing to do and it takes time but since u just edited the vegeta your already one step ahead. just edit the skin that it came with and make another skin for the shoulder pads. to compile....well just put the skin on it first then ask later.
but its ur first time so its alright, to put ur model in game replace the reference smd, i think with vegeta its like vegetanew.smd or something like that, then compile the qc. file and zang, there ya go
yeah i did(or should i say edited vegeta and turned into) a model on ussj trunks, in fact its somewhere on this forum called ussj trunks, but u need to round out the shoulders on vegeta, they look like shoulder pads