I hope my post here hasn't missed your deadline for this project, but I'll give you my input.
My advice would lean more toward the side of proper reporting, and speech writing than facts about Martial Art history. I have had training in both, and I will suggest, for the forum that you are presenting this material, you need only do a good job, and not sort out all of the controversy over history. Talk more about the struggles of the country, and the general concept of Martial Art as a method of self defense, and the role it has played in the survival of Korea. Side-notes on the debate over "Taekwondo" and its controversial origins would suffice in my opinion (unless you really want to do your research!!!).
You have taken the first step by going to a "source" that you consider useful: "Martial Talk." However, your teacher might ask how "reliable" your source is. I could tell you one story, and someone else might tell you something different. You really don't know who we are, or if we know what we are talking about. You could get several opinions, but then you would be left with sorting them out, and researching other sources to back it up. Your request for some sites to go to is more useful, but much of what you read must be presented in your speech as speculation, opinions, personal accounts, or belief of the author, and not necessarily stated as fact (even if the author thinks it is a fact).
If you don't mind me giving a little writing advice, make an outline numbering your main topic and sub-topics. One writing structure you can use is: Introduction, body, conclusion. Think of an important statement, or point you would like to make (a thesis). Introduce yourself, and the topic. Present the opening remarks leading up to your thesis, then state your thesis clearly so that it is understood that is the point you are trying to make (be sure it is a point you can prove with facts).
After that, add a little about your own experience in the Martial Art to qualify your statements, and give credibility to any opinions you might add (Don't dwell on yourself though). Keep a good flow from one section to the next. Use a little humor, but don't try to be a comic. The body of the report should always work to support the thesis (stay on topic). Your conclusion should sum up the entire report in one paragraph and restate your thesis, "therefore, that is why some people consider the Martail Art to be . . . ").
Inroduction: Thesis
....Body: Argument 1
...........Examples / support
....Argument 2
...........Examples / support
Conclusion (restate thesis).
For a "narrative" structure, tell about the events in the order they happened:
If you are going to use a "comparrison an contrast" structure (IE: old Martial Art to new, or Self Defense and sport, etc.), describe each item, and find ways they are similar, or differ.
(The Scott Foresman Handbook for Writers, 2002)
Give credit to references used and be prepared to cite your sources as I just did in this informal format. Also, don't overdo the demonstration part. Keep it simple and safe, and only do what you are really good at.
If you already knew all this, then perhaps it will be useful to someone else who reads this thread. Now go do a "Google" search for WWII history, Korean history, Taekwondo history, General Choi Hong Hi, The Korea Taekwondo Association (KTA), the World Taekwondo Federation (WTF), the International Taekwondo Federation (ITF) and the "Five Kwans of Taekwondo." Good luck!
