The recent Dictionary of Art is particularly valuable. This new publication provides excellent articles on many topics, and often includes good bibliographies. An excellent place to start. Scholarly and comprehensive coverage of world art, with many plates and extensive, though dated, bibliographies. A guide to locating entries on major artists in reference books.
Most entries are in English.
Contains extensive bibliographies. Each edition covers several hundred modern artists. These sources will help you work through literature on art and art history, and will provide suggestions on searching for art information, plus many sources not on this sheet. Volume 4 is an index to this extensive, though dated, bibliography. It offers links to thousand art related sites, an excellent starting point.