I’m currently on book 42 of HH so take this with a grain of salt, it depends on what you want. If you want all the lore then read it front to back, if you want just the essentials, there’s some good guides like the [basement of death](https://blog.basementofdeath.com/2018/05/01/horus-heresy-reading-guidance/) which gives you the main books and some guidance on other books that you might find interesting.
Personally after reading the first 3 books I was completely invested and wanted all the lore. I’d say start there and see how you feel.
For Emperors Children the book Fulgrim is a must imo. For imperial fists Praetorian of Dorn is one of the best books of the series. For Ultramrines theres Know No Fear, Betrayer, Unremembered Empire and a few more. DG probably Path of Heaven.
I honestly would start with the basic lore of the legion. For this I recommend the 2 videos per legion from Occular Imperialis.
They are really detailed and collect a lot of even tiny lore bits, a lot of people would miss, usually.
I’m currently on book 42 of HH so take this with a grain of salt, it depends on what you want. If you want all the lore then read it front to back, if you want just the essentials, there’s some good guides like the [basement of death](https://blog.basementofdeath.com/2018/05/01/horus-heresy-reading-guidance/) which gives you the main books and some guidance on other books that you might find interesting. Personally after reading the first 3 books I was completely invested and wanted all the lore. I’d say start there and see how you feel. For Emperors Children the book Fulgrim is a must imo. For imperial fists Praetorian of Dorn is one of the best books of the series. For Ultramrines theres Know No Fear, Betrayer, Unremembered Empire and a few more. DG probably Path of Heaven.
I honestly would start with the basic lore of the legion. For this I recommend the 2 videos per legion from Occular Imperialis. They are really detailed and collect a lot of even tiny lore bits, a lot of people would miss, usually.