There are plenty of online resources to help you learn more about artists books, the people who make them, and those who collect or sell their works.
The largest US collection of artists’ books is at MOMA. It has over 10,000 books including 3,700 items from Franklin Furnace (founded in 1976 by Martha Wilson as an artists’ book archive). For more information about their collection and tips for searching, please visit this site.
Many art libraries have artists' books collections, and each has its own collecting scope. Some examples of collections with good online images:
Many of these websites also have excellent images and information.
Don't forget to search for your favorite book artist's website; these often have terrific images, the artist's CV, and helpful artist statements.