The 164-page "how-to" book will explain the whole system of PhotoReading to you. The homestudy course, as well as the live seminar will teach the system to you.
In reality, most people find it very difficult to learn PhotoReading by trying to teach themselves with the how-to book only. There are exceptions.
Preview the book and see how far you can go. The homestudy course and live seminar training can bring your skill to higher levels in the shortest amount of time.