The Junior General project is one that teaches students about military history and strategy by providing various simulations using historical miniatures (paper or plastic toy soldiers), maps and counters, and matrix arguments. The simulations are designed for middle school students.
This is one of the most comprehensive search engines and websites in the world on the Vietnam War. It has over 3.2 million pages scanned materials from government and military documents, newspaper articles, photographs, maps, artifacts, sound/audio recordings, etc. Great for finding material, resources, and primary sources.
This site provides information on the different government and military leaders, significant events, and types of equipment used during the war. It also provides information on the participating countries before and during the war.