For your convenience the MBTA has a web site with routes and fairly accurate schedules at www.mbta.com...
From the address given, you're equidistant between the C and D line T's... If you take the D line located in Brookline Village, which is the fastest as it does not cross street traffic, you would be at government Center within about 20 minutes. You will be one block from Faneuil Hall and the Wharfs.
It would also stop at the Fenway (about 10 minutes) where you can walk to the Gardner Museum, MFA, etc. The E line T stops right in front of the MFA with the Gardner around the corner, but that would involve transfers.
The beauty with the Boston Public transit is that you can get everywhere relatively easily.