you are going to love your time here, it is too bad you only have two days, However if you set up an itineray you should be good to go, there is newbury street, great shops, the north end if you like italian this is the best place to get a bite, of course you have the musems and the aquariam, it all depends on what you like to do, theres fenway park if your son is a baseball fan...fanuiel hall, that is a cool place to hang out there is artists and little shops and of course food...take a tour online and see what Boston has to offer you especially if you only have two days.. you are going to have alot of fun...boy do I sound like an informaical or what LOL....and of course there is always the cambridge quilt shop, just saying is all....
Warning do not rent a car use public transportation, you can get the MBTA schedule online before you leave and I am sure the peeps at MIT will help you..you do not want to drive in Boston, I live in mass, and even I do not like driving into the boston we take the train in...