The very first books I ever read on astrology, back in 1972, were A Time for Astrology by Jess Stearn and Astrology:  The Space Age Science by Joseph Goodavage.  They're both out of print now but can still be found in used book stores.  Jess Stearn's book tells of his adventures as a writer/reporter investigating astrology but also contains some horoscope interpretations and an excellent table at the end of the book for estimating ascendants (which was incredibly helpful before the days of home computers and programs for calculating a horoscope).  Joseph Goodavage has another book currently in print called Write Your Own Horoscope which also has tables to look up planetary positions and their interpretations.

    Other astrology books, I found helpful in my early studies of astrology were Wisdom & Way of Astrology by Goswami Kriyananda, A to Z Horoscope Maker and Delineator by Llewellyn George, and Alan Oken's As Above, So Below which is included in Alan Oken's Complete Astrology.

    Since the early 1970's, there has been a blossoming in astrological writing and scholarship.  Some other books I recommend for my beginning students are:

The Only Way to Learn Astrology by Marian March and Joan McEvers.  Although this isn't (of course) the only way to learn astrology, March and McEvers have written an excellent course of study that starts with this book on beginning astrology and continues through six volumes of instruction.

   The Inner Sky by Steven Forrest, an excellent first book to read