schoolism introduction to digital painting with andrew hou
This works on a subscription model where one monthly fee grants you full access to their library of video courses. Paintable offers a super targeted library focusing on just digital painting, along with different paths you can follow depending on your skill level.
In general, I think this is not exactly a newbie guide. You can look at some of the free preview videos on the course pages to see that they do expect you to be comfortable with digital painting, at least a tiny bit(or just using a drawing tablet).
Some of these courses have a slower intro and fit much better for beginners. If you buy their Illustrator Masterclass you get access to every course so that can be a really good option for newer artists. But if you want a more focused approach I would specifically recommend their character design series along with their environment painting course.
Here is what I came up with. The line work and painting job are a bit poor for the moment. Nate will help us with those in the next few weeks so expect a new version soon. The bottom picture are explorations that I first did with pen and paper then cleaned up in Sketchbook pro.
If you are interested in painting or lighting you should definitely have a look at his blog, his work is exceptional. To me he is just as good as people with 5+ years of experience and he probably made those colour keys, two to three years after graduating.