Don, one of the best places I can think of is Perry's Creek on Vinalhaven. It is right off the thoroughfare across from Northhaven. Very secluded anchorage. You will be able to get way up in away from other boats and they have nice trails.
The next best place I know of is Holbrook Island across from Castine. Public moorings and nice trails. Less secluded although Castine is a quiet town off the beaten path.
Warren island(Isleboro) also has trails and moorings but is used quite a bit for camping, family BBQs and such.
Seal bay on Vinalhaven is a great anchorage but limited shore access and no trails.
Pulpit Harbor is a more crowded anchorage. You will see schooners overnight here. You can go to shore but no trails. Some island roads to run on. A real party atmosphere on the weekends. Similar to Snow Island or the Goslings in Casco Bay.
If you want to head a bit further east, I highly recommend Buckle Island/cove off of Swan's Island. Good place to stop if you are doing the reach. Another great place in that vicinity is Isle Au Haut which has trails in the section that is part of Acadia National Park.
Those are the ones I can think of for now. If you want less crowded, start the last week in August(or later) as the kids are back in school by then.
BTW, this post is strictly confidential. Don't tell any other sailors about these spots