I strongly emphasize that you should not overreach when planning your trip. Many distant travelers view this trip as their only chance to see northern New England, and then drive madly across the region in a valiant effort to see the Green Mountains, the White Mountains, the Maine coast, and certainly a moose up in those Maine woods -- all in a week or so.
This is a formula for disappointment, since you'll end up seeing little except the inside of your car. New England has few attractions that lend themselves to pit-stop tourism -- you pay an entry fee, look around for a few minutes, take some photos, grab a snack, and get back on the road to the next "attraction." New England is best seen by moving rather slowly, by foot or canoe or bike. The happiest visitors to the region are those who stay awhile in one spot, getting to know it more intimately through well-crafted day trips.
With that in mind, here are some suggested itineraries that can even be combined, depending on your time schedule.