These are a few personal favorites of the President
Dyer Library in Abington Massachusetts http://www.dyerlibrary.org/
The Dyer has access to Genealogy websites and an outstanding collection of Local History Books. Free-donation appreciated
Phillips Library http://www.pem.org/library/
The Phillips Library in Salem has a great collection of family books and documents relating to families who lived in Essex County. $$$
Plymouth, Massachusetts Public Library http://www.plymouthpubliclibrary.org/
As expected a great collection of family books and books pertaining to the Pilgrims who settled here in 1620. Free
Dedham Historical Society Library http://dedhamhistorical.org/research/
Send specific questions and related background information such as family charts, historical dates, book titles used, etc., so our researchers can provide you with the best possible answer. $$$
Family Search
https://www.familysearch.org/