Maine has a great set of visitor guides, its too late to get them mailed now , but do stop at the visitor center and pick one up, A few favorites not so well known
Stop in Kittery at the trading post, great sports store
Again at L.L. Bean
The Maine Wildlife Park up near Gray,
Little Moose lake region, lots of parks,
There are little fishing towns scattered along the coast, Bar Harbor being the most well know, but numerous others as well, and the food in the pier areas is wonderful.
www.maine.gov/DACF/parks/camping
There are a lot of state parks with camping that are out of the way.