High school students are often ready to expand their learning to college or adult courses. Ave Maria University (Catholic) and Hillsdale College (which is not Catholic, but has a wide range of Christian-based offerings) both offer free short classes that can serve as a supplement to a high school curriculum or an introduction to a topic the student is interested in. They also make wonderful Mother Culture classes to expand our own knowledge.

Ave Maria University currently offers classes such as The Genius of G.K. Chesterton, Catholic Bioethics, The Life and Teachings of St. Augustine, and The Foundations of America: The U.S. Constitution.

Hillsdale College offers a wide selection of offerings, including topics related to art, literature, politics, and history. (I recently took their American Art course and thoroughly enjoyed it.)