Obituaries in Massachusetts and other parts of New England can generally be found in the local town or county papers. Many obituaries for Boston and the surrounding area can be found in:
Boston Athenaeum. Index of Obituaries in Boston Newspapers, 1704-1800. Boston, Massachusetts: G. K. Hall and Company, 1968. (FHL book 974.46/B1 V28b; film 823596.)
American Antiquarian Society. Index of Obituaries in Massachusetts Centinel and Columbian Centinel, 1784 to 1840. Boston, Massachusetts: G. K. Hall and Company, 1961. (FHL book 974.4 V42i; fiche 6051402–06.) The obituaries are abstracts of the news items and are listed alphabetically.
Index of Death Notices in the Vineyard Gazette 1850-1875 http://history.vineyard.net/gazdeath.htm
Massachusetts Obituaries http://www.daddezio.com/obituary/depot/OB-MA-NDX.html
Massachusetts Data Library http://www.genealogybuff.com/ma/