The Manchester, NH airport is probably the best, there are flights there from all over the east coast. Hanover is probably an hour or so drive from there if I remember right.
If interested, you can get a connecting flight to Lebanon, NH which is next door to Hanover. There are flights from manchester, Burlington, probably Boston.
Burlington VT is about a 90 minute to 120 minute drive. Boston is at least 2 hrs.