I'm with Dave, nothing like the Penrose guide. However, if you want a "nutshell" reference and one which is colorful and easy to carry, I have Lighthouses of Maine which "Lighthouse Digest" sent as a freebie for resubscribing several years ago. It's printed on glossy paper, is 10 x 7, all in color, lists 57 Maine lighthouses and 3 Canadian (each with picture). As a nutshell reference, it gives a brief (paragraph) history with only very pertinent details (no directions) such as date and type of construction, type of lens, if in private hands, etc. And it has a foldout map. The lights are listed in clusters beginning with those in the Cape Neddick area, on to Portland, etc., all the way to Canada. I have found it very helpful. The price listed on the back is $5.95. The editor is Tim Harrison. It may still be available from "Lighthouse Digest".