It all depends on how comfortable you are in bumper-to-bumper traffic and the convoluted streets that exist in Boston. Weekdays, rush hours are terrible for the most part. Weekends is a total ****-shoot, where it can be easy in and out or just as bad as weekdays. Should you choose to drive in, head for the Government Center Parking Garage. This puts you pretty much in the middle of everything, but won't be cheap.
For the train options, there's a T station right in Downtown Foxboro, about a 5min drive from Normandy Farms. Check the Commuter Rail schedule, especially on the weekends, to be sure the schedule fits your needs.
I would suggest the train, myself, but would drive to Quincy and park at the commuter rail station there (right off Rte 93), The trains are much more frequent between Quincy and South Station, so you'll have much more flexibility in your schedule. From South Station, you'll need to take the subway to wherever you want to go.
There's so much to see in Boston, it's well worth the trouble to get in there.