Lonely Planet Korean page has good information. I took their guide book to Korea and used it to get around. It was surprisingly accurate and useful. A great investment.
Korean Culture Portal provided by the Korean Government. Lots of info on history, political history, food...
This is a site about Korean traditional Masks and Performances. Its a commercial site but the info is interesting. Andong is a good place for masks. At the folk village there are mask performance with the Andong style masks as well as a museum.
Korean Culture Service This site from New York, works with the Korean Consulate to broaden understanding about Korea. It is interesting. Relates to Korean - US information but is still useful for non Americans.
Good article on Korean Food from Wikipedia.
If you're interested in the Wonju Walking festival in the Fall then check out the IML website. International Marching League Website I walked one year and had a ball. There were people from many countries. Its not a race, just a pleasant walk to interesting sites.
