Notice: on Saturday June 9, traffic on I-93 and/or Storrow Drive is expected to be very bad. You may prefer to take the alternate directions that day.
From I-95 north/southbound you have a choice: go through downtown Boston via I-93 (more direct, but risks traffic jams) or swing wide around Boston and come in on I-90 Mass Pike (longer, with tolls, but the alternate directions do avoid Storrow Drive, which may be jammed). See either the I-93 or I-90 directions below, depending on your choice.
From I-93 north/southbound head toward downtown Boston and take the exit for Storrow Drive. (Coming from north of Boston, this is exit 26B, though 26A will also work. From the south or from the airport, this is exit 26.) Carefully follow the signs to Storrow Drive (westbound). Once on Storrow Drive, stay in the center lane when there are 3 lanes. Watch for the Kenmore Square/Fenway lefthand exit (the 2 left lanes exit). Take this exit from the center lane, not the left lane, and keep right when the exit ramp splits. Turn right at the first light, and immediately choose the larger, lefthand choice (this is Beacon Street). Proceed straight through one traffic light, then veer right at the next light, where traffic splits around a small island. You are now on Commonwealth Avenue. You'll pass a Howard Johnson hotel on your right. The 7th traffic light after the Howard Johnson is the School for the Arts building at 855 Commonwealth Avenue, where you need to check in at Gate. It will be on your right.
From I-90 (Mass Pike) eastbound take the "Cambridge/Allston" exit (on the left), pay the 50-cent toll, and stay right when the ramp splits (toward Cambridge). Turn right at the first light. You will find yourself merging onto a highway, which is Storrow Drive/Soldier Field (eastbound). Look for a small sign, "Boston University next 2 exits," and take the first exit to the right after that sign. It's a sharp right turn. Follow this little street one block uphill to the stop sign. Turn right at the stop sign onto Commonwealth Avenue, and immediately merge left out of the rightmost lane because that becomes a turn-only lane. The School for the Arts at 855 Commonwealth Avenue will be a couple of blocks ahead, on your right. This is where you need to check in at Gate.
Alternate Directions from I-90 (Mass Pike) east/westbound: take the exit for "Allston" (exit 18 if eastbound, 20 if westbound), and take the left ramp after exiting, as if you were heading for Allston. This ramp will deliver you onto Cambridge Street. On Cambridge Street, get in the middle lane. You will immediately go up-and-over an overpass. You will then go through several traffic lights, then up-and-over another overpass. At the bottom of this second overpass-hill is a traffic light (landmark: "AAW Insurance" on the right), at which turn left onto Harvard Avenue. Proceed down Harvard Ave to the next traffic light, and turn left onto Brighton Avenue. Go straight on Brighton Avenue. Brighton Avenue becomes Commonwealth Avenue (just keep going straight) at a sprawling intersection with a lot of street-car tracks (about 1/3 mile, landmark: "Ellis the Rim Man" billboard on left), at which point you are in the lower 1000s blocks of Commonwealth Avenue, with the numbers decreasing. You will go about a half mile from here. Gate is on your left at 855 Commonwealth Avenue, the parking lot is on your right at 766 Commonwealth Avenue (just past a large intersection with Route 2) and the dorm (Warren Towers) is on your right at 700 Commonwealth Avenue.