"I just wanted to know how it ends!"
It never really pays off, just read a summary.
That’s how I handled most of the New Jedi Order books, the mainline Star Wars Legacy books that take place after that, and also the Dune books by Brian Herbert and KJA.
The Star Wars books at least sound good in outline form. I’m not about to spend any time reading them for real to find out otherwise. The latter day Dune books, OTOH, sound like absolute shite even in the summary.
1d6chan is kind of a fun way to read up on it. Less serious and address some of the silliness of 40k in a tongue in cheek way.
Ciaphas Cain books are great. Any Dan Abnett works are good
As a person who’s not into the table top games, but loves the lore.
I watch/listen to a few channels:
WesHammer - www.youtube.com/channel/UCSDj6ttwzj2sr464jDdg_pA
He does a short introduction (on camera), then the rest is audio with relevant artwork and some video from the games.
Aside from the usual deep’dives into the various factions and popular characters, I enjoy his Grim Dark Story Hour vids. These focus on creepy (horror) short stories from random Warhammer books, where Wes does some voice acting as well.
The Sleepy Hollow - www.youtube.com/channel/UC86zNGwCUt5gBnizRSWSLuA
Warhammer lore (and game lore). It’s meant to be for helping people get to sleep. But I listen to it during the day. If you do use it for sleep, watch out for the super loud Youtube ads that play in the middle, if you don’t have Premium or use Peertube.
There are a lot of other Youtubers that do good content as well, like Arbitor Ian etc.
The top two are my recommendations.
Warhammer lore content made simple. My videos designed to be fun and engaging for veterans and newcomers alike as 40k can be pretty daunting and dense. I break the big complicated stuff down into simple easy to understand videos and do my best to make learning about the grim dark fun! I am a massive 40k nerd and have been deeply engrossed in this universe for almost 20 years.
For 40k, I've been watching a lot of bricky (also does non warhammer stuff so I've linked a specific video) and krakduk. (does the annoying youtuber voice, if that gets on your nerves it might not be the channel for you)
There is also the lexicanum for everything 40k, old fantasy, and age of sigmar.

Some are pretty good.
Some are pretty not.
They didn’t expect the successful of the first few that made the times best seller list, thats like massively more than they expected to sell, so they increased the planned number and the quality dropped massively as they expanded to the authors to suit.
If you read just the best books you’d still get the same favour but cut it to about 20 books or so, including the best ones in the Siege of Terra that are the actual ending.
I think this list is pretty close to the best books, you can jump off with series based on your favourite characters like Garro if they click for you: booksreadlisten.com/best-horus-heresy-books/
Couple those with the Siege of Terra but skip may be the first wall (as I detest Thorpes writing) and Mortis as its a bit boring.
People might say that way spoilers lye, however the ending was main lore even before the series started.
Try this one for the best books, you won’t have all the plot lines but the main plot was decided decades before the series even started
I’ve dislocated my shoulder fourteen times. Somewhere amongst those dislocations, I had a surgery to stop it from happening again. (It didn’t work.) However, the surgeon apparently forgot to write a prescription for the kind of medicine that one would usually have after having a shoulder sliced open. As a result, I didn’t sleep that night and, as a further result, I read the entirety of a Warhammer book.
(I’m not actually sure it shows up in this stack; I think it was a witch hunter series. Most of what I remember is some nemesis severing the tendons required to smile.)
Anyway, I haven’t dislocated my shoulder in a while - whether due to surgery or fortuity I couldn’t say - but the above is all that comes to my mind when I think of Warhammer books. Also, I now have three tiny scars about my shoulder.
That could be a couple different ones.
But, Inquisitor Gregor Eisenhorn had his ability to show emotion severed during interrogation by an enemy, and due to that person’s ineptitude at torture, he lost the connection for some nerves in his face. I’m reading that series now, having started several books too far into it and finding a ‘you’re the clone of other character from the first few books’ and needing to restart so I could get the full context
I am not far enough to know if it happens an additional time, or if he ever gets them repaired. In the book I read first (supposedly 7th in the series, by mistake) it seemed he could make some expressions but that takes place a while after the first book in the series that I’m wrapping up, where it has just recently taken place.
The first book is called Xenos, at least that’s where I’m reading that covered the paralysis part.
It never gets repaired.
It’s a trilogy of trilogies. Each with a focus one 1 person. Eisenhorn, Ravenor, Bequin.
They are great books in my opinion. I loved them.