It looks like a rainy weekend. Heard the Boston Duck tours are fun, using an old amphibious vehicle. Certainly take a trolley tour to get an overview of the city. I like foreign foods so I like walking thru Chinatown which is within walking distance of Filene's famous bargain basement. If you like window shopping, head for Newbury Street. There are some fun shops in Cambridge which you can get to on subway or by cab. Cabs are cheaper if you have 3 or 4 people traveling together. Also fun to walk thru old NorthEnd, Haymarket square area where food vendors are out with pushcarts. If weather is good go to top of John Hancock for a view of the city. Don't try to drive or park in Boston, much better to use cabs or subway. Its also a pretty walk in the Beacon Hill section were the old homes, high income people live. If you have children then Museum of Science is a good choice. Boston is an old city and one for pedestrians. Many narrow or one-way streets. Just avoid the combat zone which is right next to the theatre district - so just stay away from seedy looking areas. Have fun.

Check out http://www.boston.sidewalk.com
It's a great site--lists restaraunts, theater shows/times, special events etc...