If you're planning a trip to Maine, the state has cue sheets for 25 rides - rides that I would consider as day trips. I've done a few of them in the southern coastal area, and the ones I rode were quite enjoyable.

You can find a map with links to the areas of the state - which then goes on to link to the list of rides in that area - at http://www.exploremaine.org/bike/bike_tours.html.

You can find descriptions and some photos from the tours that I've done in my journal Exploring a small piece of the Maine coast (and New Hampshire too!).