We use a $4.95 Wal-Mart Atlas - lists all the Wal-Marts and a Trailer Life directory of campgrounds (@ 15.00 on Ebay) and a free KOA directory. If all else fails we stay in a Wal-Mart parking lot for FREE. We always ask first at the customer service counter and give them a thank you card when we leave. Here's a couple of good sites to find campgrounds:
http://www.rvparkreviews.com/ http://www.freecampgrounds.com/ and one for dumpsites:
http://www.rvdumps.com/