There is the manual right here: https://forum.paradoxplaza.com/forum/index.php?threads/darkest-hour-manual.542573/ . It might not be up to date for 1.04, but it is perfectly capable of giving you a clear understanding of the game.Are there any good guides for this game? I am a bit lost with all the differences from HoI3.
Aside from that, you have a lot of wonderful AARs to choose from. I recommend this: https://forum.paradoxplaza.com/forum/index.php?threads/aarchtung-panzer-ii-wif2.688899/ because the mechanics of WiF 2 aren't that different from vanilla DH and most mods for DH, unlike say... TRP for which I am doing an AAR right now.