The very best book for the spiritual astrology beginner (and also one of the least expensive) is Ronald Davison’s Astrology. This book starts from scratch and presents the multiple ramifications of astrology in very simple language, using an ingenious system of keywords to identify important concepts and keep the reader from becoming mired in complexities. When the reader is ready to assimilate more detail, The Astrological Aspects by Charles Carter is the best book on the subject of planetary relationship (learning what the planets mean in combination). A good cookbook-style guide to interpreting you personal horoscope for more advanced students is Alan Leo’s Key to Your Own Nativity, which gives interpretations for all the little bits and pieces which make up a horoscope; and also what factors should be taken into account when considering horoscopes and astrology in various areas of life such as marriage astrology, profession, children, and so forth. The problem for tyros is to not become bogged down in detail; and Marc Edmund Jones’ The Essentials of Astrological Analysis gives several techniques for getting a handle on the meaning of a horoscope (or if you will, a life) as a whole; i.e., cutting through the welter of detail to get down to the person’s basic motivations and drives.
The Progressed Horoscope, by Alan Leo, is the very best explanation of this area of predictive astrology for doing horoscope readings. Noel Tyl’s series of books on how to interpret transits are among the best explanations of this type of predictive technique and are well worth studying. For information on relationships astrology, the best book is Ronald Davison’s Synastry, which discusses astrology relationships and the techniques used in deciding compatibility from the horoscopes of the people involved. For more advanced students of astrology and horoscope, the most important theoretical books on astrology ever written are the Astrologia Gallica series by Jean Baptiste Morin de Villefranche, which were produced in the seventeenth century and are still extremely valuable today. The most important books in this series are Books 18 and 21, which together explain an approach to recognizing the most important elements in a given horoscope, and how to interpret them for an astrology profile. For a survey of the entire gamut of astrological knowledge as it appeared in the last century (at least up until 1976) Geoffrey Dean’s Recent Advances in Natal Astrology covers the territory exhaustively, and with critical commentary intended to separate the wheat from the chaff. For psychological astrology, you cannot do better than Bob Makransky’s Thought Forms, which is written with a spiritual New Age readership (not merely astrologers) in mind.