Okay, option one: Logan Express from Woburn. Anderson Regional Center - I don't know the exit number, but it's the one between Route 129 and Route 128/95. If you miss the exit, and it's well-marked, take the 128/95 exit south; stay in the far right lane, get off at Mishawum Road (about 300 feet), go straight through three or four sets of lights, ARTC will be on your left, just follow the signs. See
www.flylogan.com for price and schedule information... and probably better directions
Option two: preflight.com In addition to the coupon everybody's advising, the site will provide directions from a variety of access routes including, yes, 93 south.
Option three: park at the airport Sure, more expensive, but MUCH more convenient than either of the above options. Since you're only going to need four days plus a few hours, I would go with this one. There's economy parking, where they shuttle you to the terminals, and there's the central parking garage. Again, flylogan.com for information.