Other
Depicting Devotion: Illuminated Books of Hours
A digital page-by-page walk through an illuminated Middle Age Book of Hours.
British Library
British Library: Expressions of Faith: Christian Manuscripts
A series of seven Christian manuscripts from various time periods. Each manuscript is illustrated and comes with a written commentary.
Khan Academy
Khan Academy: Christianity, an Introduction for the Study of Art History
This article is an introductory historical summary of Christianity.