General

• American Presidency Project (many docs)
• Messages & Papers of the Presidents (pre-TR)
• White House
• Weekly Compilation of Pres. Docs 
• C-SPAN American Presidents
• Presidential libraries and links
• Executive Orders (summaries)
• Center for the Study of the Presidency
• VicePresidents.com
• White House Transition Project
• AEI Transition to Governing Project
• PBS American Experience: The Presidents

Speeches and Recordings

• Miller Center Multimedia Archive
• Presidential recordings (requires audio capability)
• Recordings of voices back to B. Harrison
• WhiteHouseTapes.org
• Inaugural addresses
• State of the Union (C-SPAN)
• History Place (audio of presidents)

Presidents through JFK

• George Washington papers (Lib of Cong)
• Jefferson Online Resources (U of VA)
• Thomas Jefferson papers (Lib of Cong)
• James Madison papers (Lib of Cong)
• Lincoln:  200 Years (includes debate video)
• Lincoln/Net
• Abraham Lincoln papers (Lib of Cong)
• Lincoln Speeches & Writings
• Lincoln and the Civil War
• Rutherford B. Hayes
• Theodore Roosevelt Association
• Woodrow Wilson Library
• Herbert Hoover documents
• New Deal documents
• FDR Library documents
• Truman Library
• Eisenhower Library
• Eisenhower papers
• JFK Library
• JFK speeches

• LBJ Library
• LBJ Speeches
• Nixon Library
• Nixon Era Center
• Nixon Archives
• Nixon tapes (C-SPAN audio)
• Watergate
• Nixon speeches
• Ford Library
• Carter Library
• Reagan Library
• Reagan speeches
• George H.W. Bush Library
• Independent Counsel Report on Clinton
• Clinton Presidential Center
• Clinton Presidential Documents
• Clinton speeches