http://chosonkorea.org/
This is a website focused on the Choson Dynasty in Korea (1392-1910). It is published by the Academy of Korean Studies and funded by the Korean Government. Contemporary Korean culture and values are heavily influenced by the Choson period. The site was designed with the educator in mind.
The site has sections on Culture, Confucianism, Confucianization, important historical figures, and society. It includes multimedia presentations, full length documentaries, and a myriad of historic and artistic photos. Each section links to classroom resources, which include primary source based lesson plans.
While in college, I had the opportunity to take to survey courses on Korean history. This site provides an excellent overview, but it looks as if it has not been updated for nearly a year.