Man, I used to know a guy who had a great link to some stock topography graphics. I don’t remember if they had anything for forests, but there were definitely things for mountains, tundra, desert etc.
I just tried to search for is on the tripleA boards, but I can’t seem to find anything over there since we switched Geeklog. I’ll dig around though and see if I come up with anything. I know way back when, logan wrote a simple Photoshop tutorial on how to do mountains and rivers with relief layers, but again I can’t find it with the search function. I’ll try to send an email to Felix to see if he remembers where the link is, or if he can figure what’s up with the search.