American Ancestors - from the New England Historic Genealogical Society
ancestry.com - the most popular genealogy website.
http://trees.ancestry.com/ - Ancestry's publically available family tree resource
Boston Taking Records 1800 - The taking records (later called valuation records) are government records which give an accounting of Boston residents and the taxes they were assessed.
Cemeteries of the Town of Williamsburg Mass. - compiled by Eric W. Weber
Cyndi's List of Genealogy Websites - hundreds of thousands of links, all categorized, including Massachusetts links, with many subcategories.
Family Chronicle - The "How To" Genealogy Magazine. Of course they have their own set of links.
Family Search - supported and sponsored by the Church of Jesus Christ of Latter-day Saints.
Family Search: Massachusetts Historical Records
Family Tree magazine, with a categorized list of sites.
Find A Grave - a free resource for finding the final resting places of famous folks, friends and family members.
genealogy.com - the name says it all.
My Heritage - Focuses on genealogy community building and networking.
ProGenealogists - Professional Genealogists at the Family History Library. They have an excellent list of websites.