One of our favorites:

exploredc.org

Metro (subway) Information:

• Washington Metro Area Transit Authority

Airport and AMTRAK Information:

• Ronald Reagan Washington National Airport (DCA) 
• Washington Dulles International Airport (IAD)
• Baltimore Washington International Airport (BWI)
• Union Station (Amtrak)

News and Information:

• Washington Post
• City Paper
• GW Daily Colonial
• GW Hatchet

Attractions and Entertainment:

• National Gallery of Art
• Smithsonian Institution
• National Air and Space Museum
• Washingtonian Magazine
• Kennedy Center
• Arena Stage
• Ford's Theater
• National Theater
• Washington National Cathedral

Sports Teams:

• D.C. United Soccer
• Washington Capitals
• Washington Mystics
• Washington Nationals
• Washington Redskins
• Washington Wizards