The Digital Image Guide (DIG) Method provides guidance for evaluating images using questions for analyzing, interpreting, evaluating, and comprehending an image.
Museums have digitized many of their collections. Some are clearly marked as Public Domain or with other CC licenses.
Here are a few recommended museums and digital collections.
Image databases may be subscription-based, such as Artstor (part of the JSTOR collection), or free to use, such as the Minnesota Reflections database.
Images from around the world on JSTOR. Get started by browsing all image collections, narrowing down to Artstor collections, or navigating by classifications or geography.
Digitized manuscripts, art, rare books, photographs, audio, video, and other resources from Saint Ben's and Saint John's.
Many libraries are digitizing their primary source collections. Usage rights regarding the collections are usually clearly marked, but you can always reach out to ask permission for use, especially in the educational environment.