There are many, many helpful and interesting resources online related to art and art history. Below is just a small sampling of some of these resources.
The BYU Library Special Collections make available unique, rare, and historical collections of enduring value for use by students, faculty, and other interested patrons. These items include manuscripts, rare books, original sketches, personal papers, and more. It is a rich resource for scholarly study! More information about using the collection can be located here.