VRC Image Collection - The Visual Resource Center Image Collection database supports teaching and research in art, design and art history at the CSU San Bernardino.
Oxford Art Online - An online encyclopedia of the visual arts with over 45,000 articles and over 130,000 images.
Open Access Image Database
Europeana- Digital objects from European institutions that provide open access to more than 15 million digital objects, including film material, photos, paintings, sounds, maps, manuscripts, books, newspapers and archival papers from more than 1500 European institutions.
LUNA Commons- Source for “finding valuable, educational content from digital collections“.
Digital Public Library of America (DPLA)- Discover 29,472,622 images, texts, videos, and sounds from across the United States
NGA Images (National Gallery of Art): More than 45,000 open access digital images up to 4000 pixels each are available free of charge for download and use.
Shared Shelf Commons- Shared Shelf Commons is a free, open-access library of images from libraries, archives, and museums around the world.
L'Agence Photo - More than 100,000 color transparencies and 500,000 black-and-white negatives relating to works of art in France's national museums: paintings, sculptures, decorative arts, drawings and photographs.
African & Asian Visual Artists Archive - Aavaa had grown to become the most comprehensive slide archive of contemporary visual art by artists of African and Asian descent working in the UK since the post-war period. The archive houses over 6,000 slides of artworks and exhibitions, as well as publications and videos about and by artists. There are over 200 individual artist folders, as well as curators, art historians, cultural critics and arts organization files.
Google Arts & Culture - Google partners with museums and cultural heritage institutions from around the world, and provides high-resolution images and 360-views.
Books and Articles
Generally speaking, books are not written on works of art, but on artists.
Catalogues Raisonnés (IFAR) - A searchable database listing of all the known works of an artist, either in a particular medium or all media.
Oxford Art Online - Includes peer-reviewed articles contributed by nearly 7,000 scholars from around the world, accompanied by images, bibliographies, and links to additional resources.
Art Index (H.W. Wilson) - Art Index is an art research database providing high-quality indexing for hundreds of national and international art journals, plus thousands of art dissertations. The index covers fine, decorative and commercial art, as well as photography, film and architecture.
Calisphere - Gateway to digitized images from the libraries and museums of 10 University of California campuses and more than 100 cultural heritage organizations. Includes more than 150,000 photographs, diaries, documents, oral histories and other resources. Serves as a single point of access for more than 300 UC-created websites and collections.
Searching for the artist in the ArtNet Artists A-Z list. Artist information will often include a link to a list of dealers representing the artist. Browse over 340,000 artists
Moving Image Archive - Free resource indexing over 2.5 million public domain creations; includes short, silent and art films, animations and cartoons -- all documenting our social and cultural history.