The Louvre has an excellent digital library. Explore Islamic art, Roman antiquities, and works by the masters. Be sure to explore the link for teachers.
The Teaching with Primary Sources Program works with colleges and other educational organizations to deliver professional development programs that help teachers use the Library of Congress's rich reservoir of digitized primary source materials to design challenging, high-quality instruction.
"NewLits.org is a wiki space created to collaboratively develop a rich range of specialist resources for middle school language arts/literacy educators (typically Grades 5 to 8). These resources focus variously and broadly on new literacies and digital technologies.