If you are not renting a car, it is best to book a limosine in advance. There are some buses, but the schedules are not good for reaching Menlo Park, unfortunately. Take Storrow Drive exit, and follow Storrow Drive to end, and then follow Rt. Bear left at traffic rotary, so ARCO service station is on your right. Second right is Fawcett Street.
Parking is available in the small lot in front of the building.