These sites are either free, or available via NAPL subscription.
American Ancestors by New England Historic Genealogical Society
Ancestry.com Library Edition (must be at the NAPL to access)
Family Search Mormon databases
Castle Garden (New York immigration before Ellis Island: 1820–1891) Scroll to bottom of page for links and search tips.
Massachusetts State Census 1855 & 1865
Massachusetts Soldiers & Sailors in the Revolutionary War
Northern Berkshire District Registry of Deeds
Adams/North Adams Marriage Index to 1916
Adams/North Adams Death Index 1781 – 1917