>>5913559Books are eh for digital. Go for 'Meds Map' for a digital art course.
For traditional, this is pretty broad, but there's a few out there. Depends on what you're into though. Most people mention 'Color and Light' by James Gurney as a way to learn more about how to really get color theory down for painting.
What I learned myself Anon, is that in terms of painting, I would actually get better at drawing first, nail a few drawings that you like, and THEN paint the best drawings you've got with tracing paper.
That way you don't have to put in so much time and effort for a bad painting from the start. The biggest secret I've learned is that a good drawing = a good painting, whether you like it or not (and I fucking hate drawing, but it just 'has to be done')