G&R's, that is the best reference but before you make any concrete plans around it, use the number if provided to make sure these places are open, I've found many aren't.
Probably the best if it lists a state you're going to, is
http://shooterspagetxforums.yuku.com/directory just use the dropdown menus, first the directory to the right to see what states are listed.
If you really want a book to carry, you need a "Blacks Wing and Clay"! They are found at most clubs I go to and if you're an NSCA member, they send you one.
Surely there's a place to order one on this site
http://www.blackswingandclay.com/claydetail.asp?ID=83 but it's just about------"if it's not in there, you don't need it" type of things. It's the most complete registry there is.