Here are links to some good history sites, some of which are used as sources for the content in this site:
The History Channel
PBS History
PBS WGBH American Experience
Holocaust Museum
Spartacus Educational
Library of Congress
Oliver Stone Untold History of the United States
Eyewitness to History
National Archives
USHistoryFiles – American History Blog
The 44 Presidents of the United States
Eli Whitney and the Cotton Gin Design
US Immigration Asian-American History Timeline
A Guide To Presidential Elections
Theory of Irony – How Jesus Led To Moon Golf
HSTRY – Bringing History to the Digital Classroom
Contact me if you have a site or blog that should be added to this list.