The first three books contain just about all the information on traditional art principles that you could get from any art school. If you can absorb this knowledge (which isn't really that much compared to other subjects like philosophy or science), then all you have to do is put it into strenuous practice for years until it becomes a natural skill.
The last two books contain information on creative illustration. These are the two books can help you to move from an observational artist (drawing & painting from life or reference) to a creative illustrator (art from imagination). Hope this helps.
Alla Prima: Everything I Know About Painting - by Richard Schmid

Atlas of Human Anatomy for the Artist - by Stephen Rogers Peck

Perspective Drawing Handbook - Joseph D'Amelio

Drawing and Painting Fantasy Landscapes and Cityscapes - by Rob Alexander Martin McKenna

The Skillful Huntsman: Visual Development of a Grimm Tale at Art Center College of Design - by Khang Le, Mike Yamada, and Felix Yoon