If you are trying to piece together an individual or unit history, or simply adding to your background knowledge, there are several internet sources which you should consider. Some of the services provided by these sources can be interrogated in real time using your internet browser. The internet has transformed the accessibility of many institutions such as the Imperial War Museum and the Commonwealth War Graves Commission. In order to access any primary source materials, such as unit War Diaries in the Public Records Office archive, you will have to travel to the relevant institution to conduct a manual search of the documentation. I am always keen to learn myself. If you think the list below should be added to, please inform me. The list will certainly be expanded during the coming weeks.

The World War 1 Document Archive
A rich source of Great War documents and illustrations.
The British Public Records Office. (PRO)
Holds many essential British primary source materials.
Ministry of Defence Army Service Records.
A guide from where to obtain British Army Service Records.
The Imperial War Museum.
Like the PRO holds a wealth of primary source materials.
Historial de la Grande Guerre.
Remarkable museum on the Somme. French and English language.
The Australian's War Memorial
Essential starting point for those seeking the Oz perspective.
Gallipoli.
An important source. Good links for ANZAC researchers.
The Gallipoli Association.
A wonderful source of detailed information on the peninsula.
The Canadian's War Memorial
Another key resource for people interested in Canada's role.
Soldiers of the Canadian Expeditionary Force - 1914-18.
An online database of remarkable extent & quality.
A useful list of Military Museums.
Lists dozens of military museums on a world wide basis.
The Hellfire-corner web site.
Full of interest. A quality web-site for the enthusiast.
The Western Front Association.
The principal association. Runs a very informative web site.
World War 1. Trenches on the Web…....
Big site encompassing many perspectives, full of detail.
The War in the Air.
Interesting detail on all aspects of the war in the air.
The American Expeditionary Forces in the Great War.
Follows the Doughboys' history during the latter years of the war.
An Encyclopedia of the First World War.
A helpful starting point for a thousand school research projects.
The Commonwealth War Graves Commission.
Includes an online database of British and Empire casualties.
The "In Flanders Fields" museum at Ypres.
Lots of factual material including a timeline of important events.
The Great War.
An interesting and personal archive.
Regiments of the British Land Forces.
Key source of data on the regiments and Corps of the British Army.
The Tank Museum at Bovington.
Recently updated and improved site of The Tank Museum.