For articles, images, and ideas.
Each of these websites will provide a good deal of information about a multitude of topics. This can be helpful at the beginning of a research process as you are formulating your thesis and narrowing down your research.
ARTstor is a great place to find images, expand keywords, and explore artists. To access ARTstor tutorial videos, visit the ARTstor YouTube channel by clicking here. ARTstor also has subject guides for a variety of general subjects - with keyword suggestions, search tips, and collection contents.
Artsy is a good place to look for images related to a specific theme. Many of these works are for sale but you are free to look at them, take notes, sketch.
CAMIO (Catalog of Art Museum Images Online) Catalog of Art Museum Images Online is a growing online collection documenting works of art from around the world. Images, text and multimedia represent a broad range of works of art from prehistoric to contemporary times from the collections of prominent museums.
Flickr Creative Commons Flickr Creative Commons is where Flickr users share images that can be used with proper attribution. "Creative Commons is a non-profit that offers an alternative to full copyright." from the website
LIFE Photo Archive hosted by Google Photographs from the LIFE photo archive, stretching from the 1750's to today.
VADS (Visual Arts Data Service) Online resource of freely available images in art and design (based in the UK). A alternative to ARTstor.
Wikimedia is an open source repository of images.