Agreed on Dan Carlin and if i may add TheGreatWar youtube channel. https://www.youtube.com/user/TheGreatWar They have videos from the british pathé and do week to week 100 years ago to today recaps.

There is a lot of stuff and it won't end for a few years. Also interesting is they cover things like the infantry uniforms, the guns in use at the time etc.. Highly recommended.