Massachusetts Legislature - Government site with constitution, general court rules, laws, bills, budget, legislators, and events.
Massachusetts State Library - Acts and Resolves, 1892-2009.
Openstates.org - Laws, bills, legislators, and events for all 50 states. Updates and bill tracking available via rss feed.
LexisNexis Academic - Searchable Annotated Laws of Massachusetts, constitution, and court rules. (MIT only)
Boston Redevelopment Authority - Planning and development information related to City of Boston.
Mass.gov - Official web site of the Commonwealth of Massachusetts. Includes city and town information.
Mass Facts - Boston.com resource which includes lobbyists, homicide map, campaign contributions, health code inspection records, and more.
Massachusetts State Archive - Repository of Massachusetts public records.
Vital Statistics of Massachusetts - From Massachusetts State Library.