These classes are not designed nor intended to be a replacement for a comprehensive overview of the Divine Principle. You must be familiar with the Divine Principle in order to gain the most value from these classes. They focus only on key topics of the Divine Principle, and often in unique and thought-provoking ways. There are many excellent sources available on the internet and from the Unification Church movement to study a comprehensive overview of the Divine Principle. If you cannot find one, here are a couple of resources you might find helpful... 

Introducing the Divine Principle (for tablets)
Introducing the Divine Principle
Overview of the Divine Principle PowerPoint

In addition, the following link contains good introductory resources:

Unification Study Homepage