The Warhammer 40,000 universe is one of the biggest fictional realms out there. People dedicate their entire lives to this fictional hell of a universe and still won't know it all. That can make stepping into Warhammer 40,000 intimidating, as while you might like the look of a Space Marine, or want to get into it because you have friends who are, you may not know where to start. Well, look no further as we've got ten books that can help you tell your servitors from your skitarii.
This book is what took me from someone casually interested in Warhammer to a fully fledged fan, but it might not do the same for you. Dan Abnett's introduction into the Horus Heresy is set 10,000 years before the current events of Warhammer 40,000, but it is the defining event of the Imperium, so you probably want to know a bit about it. The Heresy isn't summed up in this one book, not even close, and you need to read False Gods and Galaxy in Flames to even really get started on the Heresy, but this is a tremendous introduction into the world of Space Marines. The fatherly relationship with their Primarch, the brotherly relationship with each other, and it develops them as characters beyond faceless killing machines.
This is more of a recommendation for the Night Lords trilogy from Dembski-Bowden than it is just a nod to Soul Hunter, as all three books are often regarded as the best novels centred around Chaos. That is in part to the Night Lords themselves, who remain an edgelord's best friend and one of the more interesting legions that betrayed the Emperor all those years ago. If you've read up to Galaxy in Flames and wonder how some Space Marines could turn against the big golden goose that is the Emperor, you might want to venture into the Night Lords trilogy.
Jumping away from Space Marines to the high-flying Aeronautica Imperialis, Outgunned certainly has more of a niche focus than the galaxy-sweeping conflict of the Horus Heresy, but that is often where Warhammer 40,000 books are at their best. Lucille von Shard is one of the more recent stand-out characters of Warhammer 40,000, and while The Trial of Lucille Von Shard is technically the beginning of her story, Outgunned stands on its own as a great introduction, while feeding you interesting information on the propaganda machine of the Imperium, too.
If you're just looking to get swept up in the impossible scale of Warhammer 40,000, there are few events better than the Fall of Cadia. In what proves to be one of the most meaningful events in Warhammer 40,000's lore, Abaddon the Despoiler, who is effectively the head honcho of the Chaos forces nowadays, has committed all of his forces to destroying Cadia, one of the most important worlds the Imperium has. In this epic conflict, you'll find plenty of named characters on both sides battling it out in what truly feels like a battle that has the fate of the galaxy at stake.
We're ditching the Imperium focus for a moment, as while it is the easiest faction to focus on when you're perusing the Black Library, there are plenty of other factions and species in the galaxy. The Infinite and the Divine is another Robert Rath novel, focusing on two Necron characters: Trazyn the Infinite and Orikan the Diviner. These two have a rivalry spanning millennia, and while they are each up there with Warhammer's strongest characters, they'd rather use their powers to build their personal collections. Collections of what, you ask? Well, pretty much everything and anything.
There is no one having a better time in Warhammer 40,000 than an Ork. They're born to fight, and that's a lot of what the setting revolves around. However, this can make them a bit tricky to write a novel about. Not if your name's Mike Brooks, though, as this author has delivered a series of brilliant Ork books from their POV, showing an understanding of an alien race that grows through each page like the fungi Orks are made of. If you're a fan of big green cockney killing machines, there isn't much better than Brutal Kunnin' and its sequels Warboss and Da Big Dakka.
2017's Dark Imperium had a lot of work to do. Haley here is tasked with laying a lot of ground work for the new Primaris Space Marines as well as the return of the Primarch Roboute Guilleman, and while at times this book can feel like it is doing work for the universe more than telling a story, the trilogy as a whole quickly finds its feet and serves as a great read. If you're wondering why some Space Marines look different from others, and why something called a Primarch coming back feels like a big deal, then you'll likely want to pick up the Dark Imperium books.
A lot of people point to the Ciaphas Cain novels almost as if they're parody, as they can take a lighter look at the events of Warhammer 40,000, but that would be a disservice to the excellent storytelling they contain. Ciaphas Cain's tales of daring do produce plenty of smiles and chuckles, but the character has been built over years and years, developed into one of Warhammer's best and a top pick for the upcoming Warhammer 40,000 live-action series from Amazon.
While both the Ciaphas Cain and Gaunt's Ghosts stories focus on the Imperial Guard - which are essentially the rank and file of the Imperium's troops - they have wildly different approaches and focuses. If you're not a fan of the tone in Ciaphas Cain, Gaunt's Ghosts could be for you, as it focuses on trench warfare, deception, and a small force hoping to find some way to survive in the dark recesses of enemy territory.
Away from the dirt and blood of the battlefields, another war wages in the Imperium, one of the Inquisition against the internal threats facing humanity in the far-distant future. If you wonder how a society like the Imperium functions, Xenos and the Eisenhorn books are a tremendous introduction. The best way to approach Warhammer 40,000 is bit by bit, slowly uncovering the universe through one specific part of it. You shouldn't be surprised to see Dan Abnett here again, as honestly any book by him is going to serve as a great novel as well as a great Warhammer 40,000 story.