Digital Public Library of America: America During the 1918 Influenza Epidemic Great overview!
National Archives: The Deadly Virus (explore the whole site!)
National Geographic Reference: What is Influenza?
PBS Documentary Site: Influenza 1918 (explore the whole site!)
PBS Influenza 1918: Biography of Rupert Blue, US Surgeon General
PBS Influenza 1918: Influenza Letter Primary source!
Smithsonian Mag: How the Horrific 1918 Flu Spread Across America
Stanford University: Influenza Pandemic of 1918
Stanford University: The Public Health Response
YouTube/TED Talks: What can we learn from the 1918 flu? (21 minutes)