mattsocr,
Here are a few ideas for you. I have a Backcountry adventure book for Cali and love it. It has everything from trails, to ratings and direction. Backcountry Adventures Books
I found this web site with a google search. It seemed to be preaty good. More info

I would also try your local Barnes & Noble or other LARGE book store. Barnes & Noble Web page They will usually have a section on offroad trail books. Hope that helps a little. Just remember, once you go offroad just a little, you will want to try more. Its addicting.
Good luck and happy trails.


Casper