Finding a good campsite is quite often like finding a decent wine or a good scotch; there's a lot of hits and misses. Here are some simple suggestions:
1. DeLorme Atlases are excellent sources for each state. The down side is that they are large and don't pack well. But, nevertheless, they're a good research tool.
2. State websites (e.g. www.state.pa.us
) are getting better and better; especially with the listings and descriptions of state parks. The setup for Pennsylvania allows you to make online reservations and gives a pretty good description of the campsite (shady, open) and the distances to facilities and neighboring campsites. Whether it's relevant to your trip or not, most state parks do not allow alcohol, but do a pretty good job of policing the area.
3. National forest campsites are fairly primitive. Be advised that you may find yourself looking at a tent site, a ten ton picnic table and a pit toilet, but no water.
4. National parks have some pretty good campsites, allow alcohol, but are so understaffed that policing (noise, security, etc.) is almost non-existent.
5. Private campsites can range from wonderful to atrocious. Go online and check their websites. Most of these sites have a gallery where you can see some pictures and a rough map of the campground. If you're tenting, how close do you want to be to the RV campers? (Not to offend those of you who own RV's, like me, but it's hard to relate to nature when the neighbor's are catching reruns of Gilligan's Island and you spend the rest of the night trying to get the theme song out of your head.) Most campgrounds that cater to large RV's (Such as KOA) are also going to be close to highways and not tucked away on some narrow two lane twisty.
6. Ask around and see if anyone else has traveled your route and camped along the way.
7. Finally, if you're planning ahead, use Google Earth to look at some of the campsites. Aerial and satellite shots can be pretty useful when you start looking at campsites.
I've been doing this kind of traveling and camping for 40+ years and I've found some fantastic campgrounds that I'd go back to in a NY minute. Others I'd pass up and sleep on a park bench outside a bus depot.
And don't forget to check all that gear before you head out.