Metrobus 5A Dulles International Airport (IAD) to downtown Washington

http://living-in-washingtondc.com/metrobus5a-dullesairport-washingtondc.php

Walking route starting from l’Enfant Plaza Metro to Lincoln Memorial, Vietnam Veterans Memorial, Washington Monument, The White House,  National Archive, Capitol Building and Library of Congress

http://bit.ly/RjjgHz

Lonely Planet Washington tips

http://www.lonelyplanet.com/usa/washington-dc/travel-tips-and-articles

48 hours in Washington

http://www.lonelyplanet.com/usa/washington-dc/travel-tips-and-articles/63355#