Greetings! What a great topic to learn more about, and a popular one at that! AskHistorians has plenty of excellent resources collected over many years of answering and weighing in on questions/discussions about the War to End All Wars, and it is easy to see why that section of the FAQ and Booklist are among the largest.

For my own tuppence on the matter, see this previous writeup of mine which gives an overview of the “top 3” reads for a more general history of the war from both a military, political, and social standpoint. To get started, I would highly recommend picking up a copy of Michael Howard's The First World War: A Very Short Introduction, which does an excellent job of summarising such a complex topic in about 200 pages or so of easily readable text (and not to mention, provides plenty of further reading at the end). For even more shameless plugs, see this Saturday Showcase post about the MAIN (Militarism, Alliances, Imperialism, and Nationalism) causes of World War I as a flawed acronym, and this more recent Monday Methods writeup on the historiographical approaches to the Origins of the First World War (both are sizable, so get yourself a glass of some nice beverage before reading). When it comes to the military history of the First World War, u/IlluminatiRex is much more well-versed than I am in the various theatres of war and the actual operations. As I like to remark, I focus on what happened *to make* the guns start firing, he specialises on what happened *whilst* the guns were firing. I would therefore recommend searching through his profile for any posts which catch your eye, and doing this with any other flairs with an expertise in World War I (in one way or another) is a great way to add to the reading.

Hope this helps, and happy history researching!