This link has a lot of good info on NF campgrounds, not about dispersed camping. Also, it isn't perfect like most stuff out there!!! As mentioned, Google Earth is a great site for snooping!!
http://www.forestcamping.com/dow/list/nflist.htm
Another good source of info is the Moon camping guides. They have lots of books for western camping stuff.
We almost exclusively stay in forests and non-campground areas, and so far have not had any real nasty occurrences with our past 27ft trailer and now with our 34ft trailer. But we do more checking before heading into the woods now!!
