British Library
British Library: Expressions of Faith: Islamic Manuscripts
A series of seven Islamic manuscripts from various time periods with illustrations and written commentary.
Princeton University
Princeton University: Maps of the Islamic Middle East
This site from the Princeton University includes a map collection from Roolvink's "Atlas of the Middle East" with a variety of historical maps on Islam.
Syracuse University
Syracuse University: The Conquests of Islam
This map illustrates the Islamic conquests from 622AD to 740AD in the two centuries following Mohammed's death.