When HH and I were full-time RVing we worked one summer for Woodall's Campground Directories, which is an excellent publication to buy if you're serious about camping or RVing. They have lisitings online at
http://www.woodalls.com/ but if you're traveling and can't get to a computer, the books are wonderful and chock-full of information. You can buy them online or at any large bookseller like Barnes & Noble, BooksAMillion, etc. you can get the Big Book that covers the whole nation, or you can get regionalized publications.
Our job was to travel to each and every privately-owned campround & RV park in our assigned states, which were Oklahoma, Idaho and Wyoming. Needless to say, we had to criss-cross each of these states to make all of our stops! Once there, we inspected each campground & RV park and rated it for the book.
It was a fun and interesting job that took us to places we wouldn't have ordinarily thought to go...nd we met about a zillion people who shared our love of RVing!