Artcyclopedia provides great art online, from over 8,000 famous painters, sculptors, and photographers, at art museum sites and image archives worldwide.
This site includes an excellent “Timeline of Art History”, which extends from prehistory to the present day.
This government-sponsored site provides online tours, teaching resources, and an outstanding art collection.
This is a site which includes information on major modern and contemporary visual artists. It contains material on each artist with a portrait, brief biography, links to articles, essays and interviews, and more.