University of Hamburg
University of Hamburg: Chloroplasts and Other Plastids
This site provides detailed information on chloroplasts. Explains the many duties that chloroplasts perform and why they are so important. Good diagrams.
Biology Pages
Kimball's Biology Pages: Chloroplasts
This site touches on all the high points of chloroplasts. Includes pictures and diagrams, as well as links to more detailed information.
City University of New York
Brooklyn College: The World of Cells: Plastids
The structure is described well, but the illustration is not very useful.