Download and print a copy of the
MBTA subway map. Then pick a CG at the end of one of the routes. If you're a rookie, you do not want to drive in downtown Boston. Natives are used to driving with one hand on the wheel and one hand on the horn.
Seriously, the MBTA goes everywhere you might want to go and you can buy a "Charlie Card" good for several days. Its changed a lot since the Kingston Trio recorded their song in 1959 about "Charlie and the MTA" who got lost underneath the streets of Boston and asked the question "will he ever return". There's so much history and so much fresh seafood that you'll love your visit.