This is a starting point for collating free, web-based resources available to editors, as well as indexes to help point to sources. Please feel free to add new resources with a URL to the site, and a brief description. Don't worry too much about presentation or organization, this is just a draft. Add new headings as needed.
Over 1,200 (and growing) books published by the Metropolitan Museum of Art, New York, up to c. 2009, fully available to download as PDFs (though content is still copyrighted) from the Thomas J. Watson Library at the MMA. Exhibition and collection catalogues, many very large and well-illustrated, and much else. Also useful for general history etc.