Boston Logan is a primary or secondary hub for a number of airlines. Some of the more common airlines which offer service to Boston include:
Amtrak service is also available, terminating at South Station.
If you plan to travel around the Boston Area, a really good value is the $15/week MBTA LinkPass. This will allow you to use any of the subway or busses in the Boston and Cambridge area
ZipCar serves Boston, and is a reasonable alternative to traditional car rental for short trips.