So here's a question from yesterday where people went into a partial answer for what you're asking-- new players trying to jump all the way back to the beginning which isn't all *that* relevant to today if you want to play. The 70's were a wild time. The lore starts to settle down by the 1980s. https://www.reddit.com/r/DungeonsAndDragons/comments/1uelj75/what_is_the_true_beginning/ If you're interested in play, read the Player's Handbook-- it's a good resource in general. There are multiple historical accounts of the early days, but for an overview I'd start with Art & Arcana as a primer: https://www.amazon.com/Dungeons-Dragons-Art-Arcana-History/dp/0399580948/140-0701291-9829648 It's produced by the D&D folks, but it's reasonably fair about some of the early issues. The current owners of the brand weren't involved with the TSR days anyway. The other two books in the series: Lore & Legends tells the history of 5th edition specifically, which was particularly important product after 4th edition faltered (and their Hail Mary pass paid off big time with 5th edition being the most wildly successful at that point) and the Worlds & Realms book that gives an overview of the various different and unrelated settings that have been and are still being used. None are overly technical, none have game mechanics. You can delve into the history and politics later once you have a foundation.
