Writing about art is different from other essays, you must learn to describe and analyze what you see. The library has many books that will walk you through the process of critiquing art. Search the Library Catalog in the subject search box, type in the term art criticism. You can also check out these sites:
For background information, definition of a term, and biographies, you can use these resources:
Google Arts & Culture Free Web
(Google) A collaborative project of Google and 151 acclaimed art partners from across 40 countries to include over 30,000 works of art from sculpture to architecture and drawings, all in one page.