sorry, can't figure this out

Sorry if this is a stupid question, but when if I was to add a new ship to the game, how exactly do I make it so that there is a picture when I try to look at the ship stats in the shipyard? (20000's... got that part figured out)

It isn't a stupid question - it's pretty common actually and as such is answered in the FAQ topic pinned to the top of this board. The secret is simply to add the ID of your pict to the ship's desc resource.