Billerica Public Library databases including vital statistics, cemetery indexes, photos and maps for the town in Middlesex County, about 20 miles northwest of Boston
Boston Athenaeum digital collection including Boston Directory 1789-1900, manuscripts, photos, prints and rare books
Boston Historic Burying Grounds Initiative listing of grave markers of historic burying grounds in Boston, useful since early death records in Boston are far from complete
Boston 1775 a look at history at the very beginning of the Revolution
Boston Streets from Tufts Digital Collections and Archives, with city directories, zoomable maps and photographs, cowpaths mapping tool to plot images and directory information on a map
Concord Free Public Library surveys drawn by Henry David Thoreau, gravemarker data and Concord history
Holbrook Collection $ images of Massachusetts town and county vital records from 1620 to 1988, ancestry subscription required or free at many libraries
Early Vital Records of Massachusetts From 1600 to 1850 John Slaughter’s collection of transcribed Massachusetts Vital Records, indexed by both town and surname
Massachusetts Archives collection of searchable documents from 1629 to 1799, transcribed immigrant records from 1848 to 1891
Massachusetts Board of Library Commissioners links to digital collections, (Find Books and Magazines Online menu)
Massachusetts Board of Library Commissioners (MBLC) – Manuscripts, Archives & Special Collections  find manuscripts, archives and special collections located in Massachusetts libraries (public and private), archives, historical societies, and town clerk’s offices
Massachusetts Genealogy a directory of more than 18,000 record sources for doing genealogy in Massachusetts, organized by county, town and record type.
Middlesex County Massachusetts Probate Records  collection of probate records, including wills, administrations and guardianships for the years between 1648 and 1871 for one of the four original Masssachusetts counties, parent of both Worcester and Hampshire Counties
Native American Deeds  records of land transfers between the Native American Indians and the English settlers in Essex County
Northeast Massachusetts Digital Library history collections including Antiquarian Papers from the Ipswich Public Library
The Pioneers of Massachusetts (1620-1650) Charles Hentry Pope’s 1900 book of 5000 settlers mentioned in the records of the Commonwealth of Massachusetts between 1620 and 1650
Plymouth Colony Pages resources for colonial ancestors in New Plymouth Colony in what is now Barnstable, Bristol and Plymouth Counties in Massachusetts
Records and Files of the Quarterly Courts of Essex County transcribed and abstracted records from the original court manuscript for Essex County, Massachusetts from 1636 to 1686
Salem Massachusetts Historic Deeds browsable digitized images from the first twenty books of Essex County, Massachusetts land records, from 1641 to 1709
Salem Witch Trials Documentary Archive and Transcription Project a collection of court records, record books, letters, sermons, diaries and maps from the Salem Witch Trials
Sturgis Library, Barnstable, Massachusetts on Cape Cod has newspaper archives and a digital archival database with manuscripts, early land deeds, photos and postcards
Watertown Free Public Library online images, maps and city directories (Find Books and Magazines Online menu)

Also see links for New England