Likewise with Master of Mankind - it's a must read, but will be better if you read more of the earlier books first to build up to it. I loved Praetorian of Dorn, but start with earlier books first. The Thousdand Sons/Space Wolves story is good if you're interested in either of those. I strongly recommend The First Heretic, Know No Fear, and Betrayer. If there are arcs you aren't interested in, you can freely ignore them and it won't hurt. Skipping books within an arc is usually fine, not ideal, but you'll still be able to figure out what's happening.
Word of warning, some books are better than others. Then pick an arc you think you'll like, and go from there.
Start with the first 4 (Horus Rising -> Flight of the Eisenstein), and I'd strongly recommend Fulgrim after that. I found charts like this helped enormously: (jpeg version )
/u/Ghoul_Stars’ Video Journey Through 40kĪbsolutely you should pick and choose, but there are lots of little story arcs that progress between books, so order does matter. /u/Jackeyblob's Warhammer 40K Lore Documents AIO. /u/JIDF-Shill's Horus Heresy comprehensive reading order. Please review the short conversation blacklist on our wiki before commenting or posting. Rule 10: Certain topics are considered too controversial and tend to always end in arguments, rule-breaking, and reports. Discussion threads/comments are welcome but must be appropriately marked with spoiler tags and have no revealing information in the post title. Rule 9: No excerpts from a novel (novellas/short stories excluded) released within the last 30 days, so that there is time for others to read it. If you can't get to the point in a few paragraphs, it might not be worth posting. Excerpts must also be a "reasonable length", page long direct copies are not permitted. Rule 8: Posts containing novel excerpts must be supported by at least a paragraph describing why this moment is important, be it a grand revelation in the lore or a critical turning point in a character design. Fan fiction must be labeled, such as using to denote such a post. You may transcribe the text, however, and we request that you cite the book it came from. Rule 7: Official lore and fan fiction/fluff are welcome, but posting screenshots of official Games Workshop and/or Black Library material is not allowed. Such posts/comments will be removed and bans may apply. Making judgement or directing your posts/comments at individual users is not a good faith effort. Pointing out or analyzing the political references, satire, and allegories in the lore is okay, provided it is in an objective, academic manor. Rule 6: No opinion-based, real-world politics. Please also do not post/discuss things that are generally off-topic to 40k lore. Please do not post/discuss rules or tactics of the tabletop, painting, building, or miniatures. Rule 5: This subreddit is for discussion of 40k lore only. Do your best to provide lore-based reasoning behind your answer. Rule 4c: All hypothetical question posts must make an effort to answer the question. While these are allowed in specific cases, you must also provide a summary of the work, a specific reason you are posting, and credit to the original creator. Rule 4b: Do not post just links (YouTube, Imgur, Bell of Lost Souls, etc). This also includes text blocks consisting of Ork-speak, which should be posted at /r/40kOrkScience instead. This includes "who would win" and broad "what if" scenarios. Rule 4: No Memes, shitposts, or low-effort posts/comments. To add a spoiler to one of your comments, simply wrap it in exclamation marks and arrows >!!!Spoilers go here!< This is the result: Spoilers go here.
Rule 3: Please use SPOILER tags when necessary. Posts featuring self-promotion will be removed. Please don't use this as a platform to promote your blog, crowdfunding, or anything of the ilk. Hate speech, trolling, and aggressive behavior will not be tolerated, and may result in a ban. Failure to do so may result in investigation by the Inquisition. Set your 40kLore flair via the wondrous Flair Selection Page. A subreddit for the lore and stories encompassing the dark future of the 41st millennium.