Maine Boats, Harbors and Homes magazine has an online magazine to go with their print version. This section that local Ben Ellison (some may know him through his Panbo blog) does, is especially useful for the Penobscot Bay and mid coast area.

He scours the coastline looking for interesting places along the way and gives good real info concerning anchorages and shore access and other details. Ellison finds place I wasn't aware of and I've been sailing this area for over a decade now.