is the site sponsored by the state of Maine for bicycle tourists. They publish "Maine Bicycle Map" which could be very helpful.
Whether or not "It is worthwhile" depends on what you want to experience on your tour. We have a 3000 mile coast line and several islands accessable by ferry; we have huge forests and lakes to explore. Almost anything you could wish for in the way of adventure, you could probably find up here. I would make this suggestion: plan your trip for before Memorial Day or after Labor Day as the tourist automobile traffic, along the coast, is quite heavy. There are several books dealing with Maine's bike touring available at bookstores and even libraries. Good Luck.
That Adventure Cyling article is pretty neat; the gist is that fall is the best time to tour Maine by bike, once all the tourists and summer residents are off the roads. I note that their is an AIDS ride next Labor Day weekend from Montreal to the Maine Coast, 400 miles in five days, fully supported. There's an ad in the mag.