He has taken an interest in WW1 mainly due to playing the new battlefield. But hey he wants to learn more about it and I won't argue with him. Any suggestions? I think he is wanting something with first hand accounts.
Hey there! Glad your son is interested in history.
You can find a list of books and other sources in the sidebar. Here is the direct link to the part dedicated to sources on WWI.
Good luck!
A good way to engage him through first hand accounts is Peter Englund's The Beauty and the Sorrow which is a very engaging book that follows around 20 or so individual (soldiers, civilians and everything inbetween) through the four years of war. It's a good place to start.