Go right to the source! Does your artist have a website, or are they represented by a gallery or dealer that has images of their work online? Artists' and gallery websites often link to exhibition reviews or books & catalogs that review their work, which can be a great source to find more information.
Encyclopedias and other reference sources are excellent starting points to get background information on a topic.
Important note: Reference sources usually provide general or basic information and usually should not be your main source for research. They can provide critical details on where and when an artist worked, or the central ideas around a theme or movement, but do not provide a scholarly perspective on those details. These articles often cite other research, though, and
In addition to writings by or about an individual artist, look for the original essays or manifestos that described ideas and theories around a time, place, or movement.