George Washington Papers at the Library of Congress: The complete collection online
George Washington Papers: Essays: Essays on Washington's papers
George Washington's Farewell Address: Published in the Independent Chronicle September 26, 1796. JPG images of the newspaper and full HTML text.
The Diaries of George Washington: Full text from the American Memory project at the Library of Congress.
The Papers of George Washington: "Established in 1969 ... to publish a complete edition of Washington's correspondence". A selection of annotated transcripts are available online together with a number of scholarly articles.
The Writings of George Washington from the Original Manuscript Sources: Full text of the thirty-seven volume set edited by John C. Fitzpatrick. Over 17,000 letters and documents. Part of the Washington Resources at the University of Virginia Library.
USA: Index on George Washington: Thorough list of Washington's speeches and papers. "Washington's Farewell" remains (as do most of the revolutionaries' speeches and writings), an integral part of American Literature.