The Canadian Aviation Historical Society is the oldest and largest organization in the world dedicated to the celebration and documentation of Canada's flying heritage.
The most comprehensive site on WW1 German aviation on the web. There are some english translations but most of this site is written in German.
Aero Illustrations was established to provide quality technical illustrations and diagrams for aviation, manufacturing and publishing.
Over the Front - The official website of the League of World War I Aviation Historians, our sister society in the United States.