More could be written (somehow), but you might like to start with this . If you see "[deleted]" as the author of something here detailed and authoritative on World War I, it may well have been elos_, a user account that has been deleted. This article discusses briefly things out outside the Western Front, and then in detail at the Western Front.

For the Eastern Front: for some reason, I don't see anything in the FAQ about them. You might like this by /u/DuxBelisarius , who also links to some of their previous answers.

For an example of another area, "How was the non-trench warfare of World War I was like?" had replies primarily from /u/RonPossible about the Palestine campaign.

For more reading, you might like to read the World War One section in the FAQ, and elos_'s remaining profile.

This is not to discourage discussion. More questions, data, and debate are welcome.