Cyndi's List - More then 120,000 genealogy links most of which are categorized & cross-referenced, in over 120 categories.

GenForum - Genealogy forums searchable by regions or surnames.

Family Search - Internet Genealogy Service by the Church of Jesus Christ Latter-day Saints. Genealogy on the Internet: a workshop

Family Tree Magazine - An online and print resource for genealogist.

Family Tree Searcher - Enter your family data once and this site will search multiple family tree web sites at one time.

Free Public Record Sites - A free gateway to selected searchable local, county, state and federal records Web sites. Included are some important free non-governmental sites. 

Genealogy Explained Free Genealogy Website List - 26 totally free sites

Making of America - Cornell University
 
Making of America - University of Michigan
"These two institutions are developing a thematically-related digital library documenting American social history from the antebellum period through reconstruction." They have scanned in images of entire books and journals from 1850 to 1900.

One-step Webpages by Steve Morse - One step links for searching many genealogy websites.

Surname Origins - Find out how common a surname is in different parts to the United States. Search uses the census information from various eras to track the distribution of surnames across America.