MassLegalHelp.org is a good place to start to get answers to all of your questions about disability benefits, family law issues like child support and custody, applying for public benefits such as food stamps and family aid, and getting help with housing. If you want to ask a lawyer for free advice, you can use the Dial-A-Lawyer service sponsored by the Massachusetts Bar Association. The telephone lines are only open on the first Wednesday of every month, between 5:30pm and 7:30pm, but people have been calling the volunteer lawyers for free advice since 1991. Find out more about this program here.
For general help with legal matters, you can contact Community Legal Aid if you live in central or western Massachusetts. Apply on line or call them at one of the toll-free numbers listed here.
If you live in the Boston area, call one of the hotlines staffed by the Legal Advocacy & Resource Center. To find which of the numbers you should call for your particular question, check their website here.