There is the old ski trail on Doublehead and the one on Black Mtn, long overgrown. There was once a ski trail on Bear Mtn, near where the Bear Notch rd now runs. There are the Dartmouth trails on Mooselauke. I have not skiied it but I understand there is supposed to be a dynamite glade on the mt. behind town of Twin Mt. Dunno if it is one of the twins. There's Oakes and Tuckermans, Gulf of Slides and Great Gulf. I once did a traverse between Adams and Washington on skis. There's plenty of room for exploration if you don't mind bashing trees. Personally I think most of this tree bashing stuff sucks and I'm too out of shape anymore anyways.
There are so b/c places you could never list them all here. Moosilauke is a good place to start, AMC also has a ski group, which you should get into...you won't want to go out alone anyway. In the east, b/c skiing isn't very good until late season, by then you'll know where all the good places.