None. We do not assume that incoming students know any astrology at all.
To start out, you can look at our free introduction to astrology to help you begin to learn about the symbols.
If you want to delve further, sign up for W101 Introduction to Astrological Symbolism and Practice. The objective of this first class is to learn the basics of astrological symbolism and begin to successfully synthesize that knowledge to interpret a natal chart. This includes a solid understanding of the core meanings for the planets, a basic introduction to additional sensitive points (such as dwarf planets, asteroids, and nodes), the core meaning of the signs (polarity, element, mode of action and ruling planet), the meaning of the houses by hemisphere and quadrant division, a basic introduction to house systems, and an introduction to essential dignities and dispositor trees. By learning these basics, students can understand how astrologers have added additional concepts, particularly in modern times, and be able to evaluate whether or not they agree with these additions. By the end of this course, students will be able to do a basic interpretation of a natal chart on their own.
In addition, some of our classes in the esoteric track (such as the E520 series on the soul) can be taken with little to no knowledge of astrology.