There's a plethora of information out there on the Koguryo dynasty, for those that are interested in the roots of our school. Here's a few that I've studied so far:
Great link by Lee Wha Rang:
http://www.kimsoft.com/KOREA/kogu.htm (This guy gets the most props on the internet. Everyone seems to use his information).
Wikipedia (a site I use a lot for my collegiate studies) giving Koguryo some love:
http://en.wikipedia.org/wiki/Koguryo
Another great link:
http://www.mykoguryo.com/history04.htm
Looks like it is also referred to as "Goguryeo":
http://www.mygoguryeo.net/history04.htm
Association for Asian Research:
http://www.asianresearch.org/articles/1613.html
From Japan Focus:
http://japanfocus.org/article.asp?id=518
From the Agonist Community Message Board; some, of which, is regurgitated from my links above. However, a very, very interesting read!
http://discuss.agonist.org/smf/?board=2%3baction=display%3bthreadid=16561
Just a friendly FYI!