Here are a few subject searches related to Christian art and iconography, completed through the library's catalog. Look at Books for alternate subjects:
BR- Christianity
BS- The Bible
BX- Christian Denominations
N- Visual arts
NA- Architecture
NB- Sculpture
ND- Painting
NX- Arts in general
The Dent Dictionary of Symbols in Christian Art by 
Thesaurus of religious objects : furniture, objects, linen, clothing and musical instruments of the Roman Catholic faith by 
Dictionary of Christian Art by 
Vestments and Vesture, A Manual of Liturgical Art by 
Symbols of the Christian Faith by 
Encyclopedia of Medieval Church Art by 