I've found that learning astrology is without a doubt an accumulative process, but I would like to acknowledge these sources of knowledge on this subject.
Chandra introduced me to astrology - offered me the opportunity to view life from a different perspective, for which I will be eternally grateful.
I used The Only Way to Learn Astrology, by Marion March & Joan McEvers, for some quick reference information about signs, houses and planets.
A pamphlet called the Magic of Astrology, by Donna Rose, helped me with the colour, metal, flower, incense, number, and tarot information.
Your Sun Sign as a Spiritual Guide, by J. Donald Walters, imparts spiritual wisdom for each sign, which invariably ends up being "meditate" - maybe he's got a point. He offers concise spiritual goals, directions, for each of the signs that have helped me gain a fuller understanding of each signs mission.
Astrology and Sexual Analysis, by Morris C. Goodman, I could not resist. This book attempts to draw a sexual portrait of each gender in each sign. The perspective is decidedly Hollywood, decidedly male, and yet he hits his mark often enough. I hope to filter some of this information onto these pages carefully, because it is indeed a weighty subject. Hopefully, I will have more of my own experience to draw upon by that time.
My perspective on all the various aspects of Astrology was broadened by Debbi Kempton-Smith, and her book Secrets from a Stargazers Notebook. While it looks pretty shallow from the cover, like a shabby sun sign paperback, she puts the subject forth in her own tone of voice, and she obviously has a great deal of experience with a broad range of astrological materials.
Rene Mueller's Astrological bibliography.