Update

So far everything is unwrapped, and I have a few textures made up. I still have a good amount of texturing to do, but I am expecting to at least be done with the diffuse textures for everything by the end of the week. Other supporting maps will follow those. The shot below should give you a rough idea of what stuff looks like. It's a little bit different than the original idea for the textures.
Textures are made using resources from cgtextures.com.


As far as constructing the textures I basically just took bit and pieces from photos and mixed them together. I then would use the sponge tool to desaturate stuff a bit, and use tools like burn, dodge, healing brush, paintbrush + layer blend modes, brightness/contrast, etc to get things looking how I wanted. Finally I blended a picture of some green/yellow marble over everything to keep things consistent. I will make another post showing how I created one of the textures from beginning to end in an effort to keep things organized.
Here are a few to look at: