RRpics.net is a great place for skin prep. Find one you want to model.
After that, Bdaneal had an undecorated on his site IIRC?
Do those SD-9s come with ARN? If they do, you probably want to avail yourself of that at some point (Though if you're just starting skinning, maybe wait till later, I've heard theres a process that comes with dealing with ARN, and IDK what it is, though JCitron probably does, lol, hes very knowledgeable).
Falcus