PBS
The Great War, Episode Two: Stalemate
Highlights from Episode 2 of the series, "The Great War," provide information on the "deadly stalemate." Includes information on the Schlieffen Plan, "Life in the Trenches," and "The Christmas Truce."
Other
Islandnet.com: The Gottfried Silbermann Legacy
Excellent site describing Silbermann's work on the organ as well as the development of the piano. Many interesting links to musical societies which also have musical worth.
Other
War Times Journal: Wwi Eastern Front
This site covers the eastern front of WWI from the initial Russian invasions to the eventual German advances and victories.