bITS 'N CHUNKS
I love grimoires!
The first grimoire I ever read was The Lesser Key of Solomon, probably the most famous and most easily available. This and the Pseudomonarchia Daemonum are usually what is referenced when you see some deep knowledge of obscure demons. These also present a hierarchy of demons, descriptions of their facilities and legions they command, and usually some nice old timey engravings. More importantly, the Lesser Key presents how to summon demons and get them to do your bidding without dying horribly.
Look, if demons exist I really have to ask why they are so damn subservient to humans for petty shit. Wasn't that the whole point? Man, whatever. The Lesser Key sparked my fascination with sigils though, and to this day I like incorporating them into my work and personal life. I like specifically demonic sigils and ones to call upon angels as well.
So, let's say The Lesser Key is your introduction to Satanism and you get caught reading it. What do you do? Well, first I usually say it's a historical text. The odds of summoning real demons or angels are real low. If it helps, The Lesser Key is explicitly for ritual magic purposes and actually suggests regular uninitiated people shouldn't fuck around with the material too much. I think it's also important to mention that as an occult text, The Lesser Key is notorious for listing out demons and how to employ them but it engages with heavenly powers as well for a balance. There's a prayer book within it that coordinates hosts of angels with the zodiac and hours of the day for calling upon them. That doesn't get a lot of press because it's not as cool but I find it fascinating. It totally changes how one deals with the idea of good and evil and angel versus devil, and the perception of good and evil forces.
At the end of the day, it's just a book. A good one to read, but just a book nonetheless. But if you're interested in religious philosophy and ritual magic this is the place to start.
Some other cool ones to read. The Testament of Solomon shows King Solomon as a bad ass taking out demons left and right, and will show you how to likewise be a bad ass demon slayer if you so choose. But it's more of a thematic text than an instruction guide or manual.
Other grimoires I like are the books focusing on exorcism, especially if you'd ever like to see how exorcism really works. If Satanic ceremonial magic is not your thing, there are lot of useful grimoires on natural magic and prosperity. There are modern grimoires still being produced but I don't find them as vital as the ancient texts, and it seems to me most of them are in the Wiccan tradition of creating personal spell books so I skip 'em.
Ia! If you've come this far, you're either looking for weird or you know you've found it...