If you are heading to New England, you may want to consider flying into Manchester's airport versus Logan in Boston. The Manchester Airport is smaller, newer, and has much less congestion than you will find at Logan.
I've flown into both and if I were going to New Hampshire or North Central Mass, I would take Manchester over Logan just to skip the Boston traffic.
(First off, don't be frightened by the pic...I arrived at that scene years ago in Boston and thought it was wild. Nobody was hurt). Bus Service between Manchester and points South is cheap, clean, and efficient. Concord Trailways runs hourly+ during peak hours, connecting Concord, Manchester and Boston(including Logan). From Boston, express buses run you to NYC in four hours, with free film included - but only on Peter Pan. Avoid the ghetto Greyhound. Service North of Concord is more sporadic, and East/West travel is non-existent. Still, oftentimes, I will fly into Boston, and bus to Manchester, rather than deal with traffic or forcing my relatives to do the same. Furthermore, I preferred the bus over plane and train when travelling between NYC and NH for six years - that's an endorsement.
Having lived in NYC for many years, I found Manchester taxi services to be outrageously expensive. I took a cab from downtown to the Bedford line, at Second St....and it was thirteen dollars. There are no alternatives, really. Local buses are near non-existent. But, I was aggravated. Most hotels offer complimentary transportation. Ask for it.