@kf Michael Hewitt has series of books on music theory: "Music Theory for Computer Musicians", "Harmony for CMs" and "Composition for CMs" — there might be more by now, but I only have these 3.
I already knew the basics when I read them, but I think they are really good and easy to understand, e.g. he uses not only standard music notation, but also piano roll found in most DAWs, guitar tabs, show what chords/scales/modes look like on the keyboard…
I'd recommend these books!
@m0xee thanks! Will check them out!