FIRSTWORLDWAR.COM: A remarkable site and resource for anyone studying the Great War.
THE BBC: Their history section includes much interactive material on World War One.
WIKIPEDIA: The online voluntary encyclopedia has a rather weak article on the Christmas Truce but is a good resource for all related material.
1914-1918.net: One of the best web pages about the truce including a list of all British units that took part.
USA People Search: A good overview of World War One from this people search engine.
The Western Front Association Established in 1980 by noted military historian John Giles, the Association has grown over the years to more than 6,500 members worldwide. The WFA has supported many remembrance and research projects, from the renovation of battlefield memorials, to organising care for the veterans, to re-establishing the 11 o'clock two-minute silence at the Cenotaph on the 11th November each year.
Lost Generation 1418: Discussion forum on World War One
Hellfire Corner: One of the oldest and best websites on World War One.
The Association for Military Remembrance : A report on the 1999 comemmoration of the Christmas Truce.
World War One online document archive. A fantastic resource for researchers and historians.
Khaki Devil: Suppliers of Military Uniforms, Equipment & Historical Advice
YouTube - a variety of music and videos inspired by the Christmas Truce.