for a quick overview of a topic
to develop vocabulary or keywords for searching
for suggestions for further sources
Try using a specialized reference work to get started with your research. You can browse these to spark a paper topic or look up information about a term or technology cited elsewhere.
Scholarly encyclopedias are great, authoritative ways to understand more about a topic (and always better than Wikipedia, which is not an appropriate source for academic research), and they can give you information about where to look next. But remember that these are reference tools, and as such they are usually not appropriate sources for a scholarly paper on their own.
The most authoritative and extensive encyclopedia for Art is Grove Art Online (available through Oxford Art Online) .