recommended Florida to Maine route
I agree with stockman, except I would get off I-95N in Fredericksburg, VA. Then Rt 17(N or NW) to Winchester, VA where I would pick up I-81N all the way to I-84E in Scranton, PA, to I-90E(Mass Pike), to I-290, to I-495 and then back onto I-95N. Once you are in Maine stay on 95N until Augusta, then take Rt 202 east to Rt 3 east to Belfast/Swan Lake area.
I used to travel from NC to Maine quite a bit and always thought this route was much more enjoyable than staying on I-95 the whole way. Scenery is nice and tolls are less, and if I remember right it's about 100 miles more than staying on 95 for the entire trip.
If you have AAA I'd check with them before your trip to find out if there is any construction to avoid on your planned route.