Nice!
I grew up in East Blue Hill; my family currently owns a summer home in Blue Hill and I'll be there this weekend. It's a quiet, beautiful place.
Mount Desert Island (MDI) and Acadia are incredible. Starting in Hulls Cove at the main entrance to the park, take a drive out the Ocean Drive to Sand Beach and hike the trail around Great Head (yes, that's the real name). If you like challenging terrain, on the way to Sand Beach stop at the Precipice Trail parking lot, which is on the eastern side of Champlain Mountain. The Precipice route is a steep, technical trail - nothing else like it. The trail may be closed due to nesting Peregrine Falcons, but if it is there is usually a ranger there with a telescope so you can see them.
There are a hundred other things to do in the park:
- the Beehive, North and South Bubble (with a stop at Jordan Pond House for tea and popovers), and the North and South Ridge trails up Cadillac Mountain are a few of my favorite hikes.
- visit Thunder Hole, Anenome cave and Otter Point (all along the Ocean Drive, a one-way loop through most of Acadia)
- bike/horseback ride on the Carriage Trails. you can rent bikes anywhere, and Wildwood Stables does guided horseback trips.
- take a kayak tour, or a sunset cruise aboard the Mary Todd
-take a drive up Cadillac, watch the sun come up (first place in North America that you can see it), then Jordan's Restaurant and a stack of blueberry pancakes for breakfast.
-whale watching; it's early but they'll be spotting them, seal-watching or lobster boat cruise
- rock climbing; there are several local companies that will take you out for instruction or guiding
There are a lot of great places to eat. In Blue Hill try The Fish Net (local lobster/clam joint/dairy bar), Barncastle, or Arborvine (exceptional local fine dining; The Vinery/Deepwater Brewing is their brewery and is also awesome). Perry's Lobster Shack is a true ME lobster experience in East Blue Hill on Newbury Neck; they're probably opening this week.
Bar Harbor: hard to go wrong as there there are a hundred places, but I like Mache Bistro, Havana, Stewman's (waterfront lobster), Geddy's, Parkside, Paddy's (Irish pub), Cafe This Way, Thirsty Whale (local/biker bar) Side Street, Chart Room, Rupunui's and Lompoc. If you like local beer order anything from Bar Harbor Brewing (I like their Real Ale) or Atlantic Brewing (they also have an open brewery with tours in Town Hill). If you like ice cream (or chocolate, or candy of any kind) check out Ben's and Bill's - they make about 30 different flavors and everything is made in-house.
Good restaurants in the surrounding towns on MDI as well - Southwest Harbor and Northeast Harbor are great little towns.
If you're driving up through Maine to get to the BH/MDI area, spend a day or a night in Portland; as already mentioned, it's a foodie town. Go to The Grill Room, Zapoteca (Mexican), Ri Ra (authentic Irish pub) or Street and Co (seafood) for fantastic food and drinks. Try Novare Res for at least 100 different types of beer or In 'Finity for for beer and drinks (they brew unbelievable beer and distill their own spirits). Try The Front Room or Becky's Diner for breakfast.
There is really only one LGS, Willey's in Ellsworth, which is en route from Blue Hill to Bar harbor.
It's a very good time of the year to be visiting ME. The nights are cool, days are warming up, and the huge tourist crowds have not arrived yet. Have a great trip!