Another website I use on my webpage is the Universtiy of Minnesota--Mankato museum's site. This site has an extensive timelins of Chines dynasties, information on many of these dynasties, images of Ancient Chinese artifacts, and a collection of good maps on the different Chinese dynasties. I included it for the information on the Tang and Song dynasty, as well as its links to maps that would help my stydents create their own map showing the boundries of the Tang and Song dynasties.
The web address is:
http://www.mnsu.edu/emuseum/index.shtml
Click on the first floor, and then the Ancient China portion of the display map that appears.