This is a resource post. Please add comments describing any useful information about any art-related books you have enjoyed or found useful. Links to other online book resources are welcome, especially if you say a word or two about what is available at that resource. Links can also be to Art and Perception posts with relevant information. If the information is in a comment rather than the main post, please link to the comment, which can be done by copying the link under the comment date (or the name of the commenter from the sidebar comment section).