Academic Search Premier. (EBSCOhost). Summaries of articles from over 4,000 magazines and journals, with approximately three quarters of those in full-text or full-image format.
Declassified Documents Reference System. Full-text database of previously classified documents declassified by the federal government. It includes material (from 1941 to 1998) on both domestic and international affairs from such agencies as the FBI and the CIA.
AmericanPresident.org has "information on the function, responsibilities, and organization of the modern presidency."
The Presidents was an American Experience series on PBS TV. This companion Website includes sections on the career and legacy of each of the Presidents from Washington to Bush.
The American Presidency Project, hosted by the University of California, Santa Barbara, provides access to many official documents, election results, and audio and video clips (Quicktime Player required).