http://www.visual-arts-cork.com/history-of-art-timeline.htm
a written timeline containing links to pages of interest for each event
http://www.rchoetzlein.com/art_theory_map.png
a really useful graphical representation of important events and developments in history
http://www.alifetimeofcolor.com/study/timeline.html
a grid based timeline that links to basic information, useful for finding out when the pencil was invented!
http://www.metmuseum.org/toah/
brilliant website that enables you to search by map or 1000 year period, very detailed!