I used The Long Long Trail, too, and found it an excellent source of information. The Great War Forum was a great source of help with my project (tracing my dad's movements in the First World War). I inherited the letters he wrote home to his mother from the front. Censorship prevented him from telling her where he was exactly, so he devised a code (incredibly simple) representing the area where he was. It didn't take them long on the Great War Forum to work out what he meant. Amazing then that his letters got through the censor all those years ago. My avatar is his mother.