The definition of art is as free as the form of expression itself, so there is a wide variety of titles that fall under the umbrella of art books. From instructional drawing guides and artist monographs to children's books about art, they can offer something for everyone.
We have art history books through which you can learn about the art of different regions and times with works like Nineteenth Century European Art. And then there are less conventional art books like Essential Art Therapy Exercises, which explores the benefits of art therapy.
An approachable and popular art book is the coffee table book, with titles like Architectural Digest at 100 that showcase gorgeous photographs. Technique books like Color and Light give valuable insight for realist painters. For the cinephile, there are books on cinema written by film artists, like Quentin Tarantino's Cinema Speculation.