Art reference books (encyclopedias, dictionaries, etc.) are shelved with the main collection and are borrowable. They are good sources of background material on art history, fine arts, photography, etc.
On this page is a selection of online reference works from Oxford University Press.
Concise dictionary of art terms. 2nd ed. by 
Dictionary of architecture and landscape architecture. 2nd ed. by 
Dictionary of modern and contemporary art. 2nd ed. by 
Dictionary of modern design by 
Encyclopedia of Aesthetics (2nd ed.) by 
The Oxford Companion to the Photograph by 
Oxford dictionary of American art and artists by 
Oxford dictionary of art and artists. 4th ed. by This catalogue search in Title Keyword shows how to find reference works on photography:
photograph* (dictionary OR encyclopedia*)
NB: The asterisk (*) functions as a wildcard, retrieving books with photograph or photography in the title.