The Trailer Life Campground Guide is the most popular and probably the most complete list of campgrounds. Woodalls is published by the same people and has about the same coverage, but organized differently.
Passport American (http://passport-america.com/) has a large list of campgrounds in their membership that offer half price camping. They publish a directory both in paper and on CD-ROM.
I agree with Paul re the Trailer Life Navigator CD - it's mediocre at best, either as a map software or campground guide. About the only thing is does reasonably well is to provide a list of campgrounds in the vicinity of a city or town. That's OK if you must go to a certain place and need to find a campground near by, but not very useful if you merely want to find something along your route of travel.
I returned my copy of the 2006 Navigator CD for a refund. Recommend the hardcopy Trailer Life directory instead.
Woodalls lists campgrounds that TL does not, and vice versa. There are enough differences that we find it useful to carry both guides and we purchase a new copy of each every other year, alternating so we always have the current year of one of them. I would estimate the overlap at about 80-85%. If I only carried one directory, it would be Trailer Life. However, Woodalls has better listings for smaller campgrounds and local public parks.
The other major directory is Wheelers, available in paper or CD. It is not as broad in coverage as TL or Woodalls and the information is not as comprehensive.
All of the above three are available online as well.
I googled the Woodall's and found more than I was looking for!? There are so many editions....and the regionalized ones more complete?? The west is our primary playground, however, we may take one trip to Indiana this summer... any suggestions?
Edit*** line two was to read "There are so many editions....are the regionalized ones more complete??
Is there anyone with knowledge on the Woodall's guides. There are numerous options and I am wondering if the regionalized guides are more detailed than the full version, or if they are produced to offer a lower cost alternative to someone who may only travel the different halves of North America.
Unfortunately, my guides are in the coach on the storage lot. At one time I bought both the east and west versions of Woodalls, before buying the full version. If you can get to a rally or RV show, Woodalls was selling their full version for $10 at the recent FMCA rally. That's less than I paid for each of the other two. Sorry, but I haven't done a comparison; I just use the full version.
There is another guide from Wheeler's and it is not owned by Affinity Ent., the parent company of Good Sam, Trailer Life and Camping World. But the best for directions and such is still the one from Trailer Life.
We too are members of Passport America and consider it to be the very best bargin in camping.