ARTStor
The Artstor Digital Library is an image database featuring images from some of the world's leading museums, photo archives, scholars, and artists. All images are accompanied by comprehensive metadata and are rights-cleared for educational use.
Google Art Project
Contains high-resolution images of objects from collections worldwide.
Wikimedia Commons Art
Not all of these images are high-resolution, but most of them are licensed such that you can reproduce them or include them in a course Web site.
JSTOR
Provides access to academic journal articles, ebooks, and primary sources.
Getty Research Portal
Over 100,000 online books about art and art history.
Gale OneFile: Fine Arts
Periodical database for students of drama, music, art history, and film making.
Timeline of Art History
Thousands of short essays about periods, styles, and techniques from throughout Art History.
Blouin Art Sales Index
A listing of art sales from 1970 to the present, useful for researching a specific object
Writing about art
Marjorie Munsterberg -- a professor at City College of New York -- wrote this ebook for her art classes.
Smarthistory
A solid art history reference
Art History uses a lot of specific terminology. Use the following resources to get your bearings and learn about the terms you encounter:
The Grove Dictionary of Art, edited by Jane Turner - you can explore the 34-volume set at the Library's reference desk
Smarthistory: A solid art history reference