Guns of August by Tuchman is a good read. While it covers history of the first month of the war, Tuchman has a way with a pen so it does read like a good story while still being a historical book.
Testament of Youth, which I'm currently reading, is also pretty interesting - however, it's not strictly about a war, as it is memorial of Vera Brittain, upper class women who has decided to volunteer on the front. It covers years before, during and after a war. Interesting peak into early 20th century society from ambitious women perspective, with the tragedy of Great War during her years of youth.
All Quiet On The Western Front is... well, ah, what else to say? Althou, I can throw in "Black Obelisk" by Remarque - it's set between WW1 and WW2 period, and while it is book of fiction, it shows some of the aspects of post-war life in interesting light.
When it comes to YT channels - Old Britannia does excellent, long documentaries, where he does include sources used, which is pretty important. Also Sir Manatee, however his works do cover general early 20th century times. The Great War channel has a series covering war week by week, and while project changed hands, they still do produce good videos.
I would also keep in mind *what* you're watching. Lot of AI slop and lazy human slop - it's good to remember one can just say any ♥♥♥♥♥♥♥♥ he likes, so I'd stay away from documentaries/series which don't include sources and oversimplify things, as Great War is anything but simple
EDIT, as I just remembered things
The Western Front Association and WW1 Imperial Museum also have lot of great lectures. Both can be easily found on YT. Also The Rest Is History, althou they do not focus solely on Great War
And "Not So Quiet On the Western Front"