Here is one I've used in the past: http://www.reinerstilesets.de A google search I also found this that might have something useful: http://pixabay.com

maybe here: http://www.goodtextures.com/menu/358/bark/

The things at http://www.reinerstilesets.de are great. I want to make something with those train cars and buildings, like a virtual train set or something. I had always drawn my own stuff, but it looks primitive. I do let people use the graphics I have made. I need to put them in a public drop box folder.