Check out this fun web page to learn "How to Enjoy Boston on a Shoestring Budget".
Great suggestions here, even if you have a slightly higher budget to work with than a shoestring, LOL!
Fondest memory: Learning that I don't need to fear the "T"! It's cheaper and faster to get into Boston from the airport (or Winthrop) on the "T" than it is sitting and manuvering in the traffic going thru the Sumner Tunnel. The toll is now $3.00, by the way and the "T" (subway train) is only $1.25 each way! Altho, it's even cheaper if you purchase a PASS.