Openculture.com has lists of courses that can be watched or listened to for free online. Some courses are available on YouTube, some on iTunes, and some can be viewed on both. These classes are from universities around the world and have a variety of topics to choose from. In addition to the topics below, feel free to explore any of these courses. The sections of Archealogy and Anthropology may be relevent to this class as well.
Each of these links leads to a series of lectures on YouTube that make up an entire course on World History taught at Columbia University. The Professor teaching the courses is Richard Bulliet, one of the authors of the textbook for this class. Each lecture is approximately one hour and fifteen minutes long and they are titled with the main subjects that are covered in within that time.