The State Data Center has an extensive collection of census data on population, housing, education, business, manufacturing, trade, services, government, and agriculture in Massachusetts, New England, and the United States. The data is available in machine readable format and in print in their library. They also have free data you can download from their website.
"A growing number of state publications are now available electronically, either digitized or created in digital form. These include recent documents that are published solely in electronic form and heavily-used series that have been digitized, such as Massachusetts Election Statistics and the Massachusetts Acts and Resolves."
Information relating to Massachusetts State Law including statutory law, administrative law, case law, research assistance and some historical information. Information relating to Massachusetts state law, including current and historical statutes, administrative law (The Code of Massachusetts Regulations & The Massachusetts Register), and case law, and research assistance in using these materials.
A Guide to Tracing Massachusetts Legislative History
Including the Boston Atlas, a mapping application, which has data from many city agencies, including the Assessing Department and the Boston Water and Sewer Commission, plus information from neighboring towns and the state.