United States Senate
Official site for the U.S. Senate. Contains profiles and contact information for current senators and committees as well as descriptions of legislation, Senate history and tours, and reference materials.
Wikipedia: United States Senate
Article about the upper house of the United States Congress. Features a list of members, operation, procedural quirks, and more.
National Republican Senatorial Committee (NRSC)
National Republican Senatorial Committee (NRSC) was established by Republican Members of the United States Senate to help Republican candidates develop the campaign resources they need for 2006 to maintain and grow their majority in the United States Senate.
U.S. Senate Historical Office
Presenting the development of the Senate as an institution, biographies of famous senators, interviews, photographs, essays, and special exhibits.