Book is old but in pretty good shape.
This is one of the best *basic* astrology books out there. Forrest presents the material in an easy to understand manner but does not take on a condescending tone. As I've built my astrology book collection (over 100 books), this book remains one of my favorites.
An excellent book by a highly regarded author, "The Inner Sky" takes the reader through a gradual, systematic approach to weaving together the elements of the birth chart. Though this book is dense with information, author Steven Forrest strikes an easy-going and engaging tone that encourages rather than overwhelms the reader.
Some information is given on the mechanics of how to cast a natal (birth) chart, but the primary focus is on understanding the characteristics of the houses, signs and planets, and how they interact with each other. Major aspects are covered, as well as the influence of retrograde planets. Rather than providing lists of rigid interpretations for each configuration, "The Inner Sky" teaches the reader what questions to ask, and where in the chart to look for the answers. The author takes the view that an astrological chart indicates inclination and opportunity, not irreversible fate. Most importantly, you will learn to organize the wealth of information present in the birth chart in a way that enables you to give a professional, fluid and intuitive interpretation without losing the structure of the chart.
After practicing the methods outlined in the book, you should be able to do an "in person" chart interpretation without having to stop and consult reference materials. You will learn to identify the seeds of opportunity present in whatever chart you are looking at; you will be able to articulate, for each individual, the early warning signs that they are getting 'out of balance' with themselves; and you will discover what experiences, in which life arenas, will help them re-connect with their essential self. If you could only buy one book to learn natal astrology and the basics of chart interpretation, "The Inner Sky" would serve you well. For those interested in further reading, "The Inner Sky" contains an appendix of books recommended by the author, Steven Forrest, all of which are reputable and handily broken into "beginner's" and "advanced" categories.