I have no experience in panting and drawing but I would like to start learning it in digital media. Are there any books, websites, or tutorials which teach digital painting and drawing? I use Corel Painter, but I do not want tutorials about how to use the software.
Have you tried Corel Painter´s portal? https://learn.corel.com/painting-tutorials/
I'm only going to tackle the online part, here are some of my favorites and I'll probably add to it when I have a bit more time:
Ctrl-paint is a library of free videos which covers both the traditional knowledge and the digital part
Look for artists who do online streaming to see how they work. If they're live, you might be able to ask a question or two about their process. Here's a link for Twitch but I'm guessing there are others on other services.
Lynda.com has a few paid courses about digital painting