As for Summer reading, you'll want to get familiar with your Maine authors. Nothing says Summer in Maine like Robert McCloskey's One Morning in Maine ($13) or Blueberries For Sal ($8). The best part, of course, is then visiting the same spots that McCloskey references in his stories, like heading to Bucks Harbor market for ice cream like Sal.
For a heartier read, I love E.B. White's ode to the Maine life, One Man's Meat ($12). It's the story of his move from Manhattan to a farm in Brooklin, ME. After you read it, you can stop by and see the house for yourself, complete with White's writer's cottage.