The U.S. Government
The White House: http://www.whitehouse.gov
The president's schedule, texts of speeches, press releases, transcripts of press briefings and more.
U.S. Senate: http://www.senate.gov
Find and contact your senator, check the Senate's agenda and look up roll call votes.
U.S. House of Representatives: http://www.house.gov
Find and contact your representative, check the agenda and look up roll call votes.
Tracking legislation in Congress?
Just go to the Library of Congress' Thomas Web site: http://thomas.loc.gov
Or use C-Span's Congress Guide. It has a cool feature letting you search for votes going back several years: http://www3.capwiz.com/c-span/dbq/issuesdbq/votesearch.dbq