Where can I read more about the Technique?

There are many, many books about The Alexander Technique, including some written by Alexander himself.

Some are out-of-print, but here is a list of my favorites:
Selected Books about the Alexander Technique

For beginners, the book I most recommend is:
Michael Gelb, Body Learning, Henry Holt and Company, New York, 1995

Books written by F.M. Alexander:
F.M. Alexander, Articles and Lectures, Mouritz, United Kingdom, 1995
F.M. Alexander, Man’s Supreme Inheritance, Dutton, New York, 1910
F.M. Alexander, Constructive Conscious Control of the Individual, Methuen, London, 1923
F.M. Alexander, The Use of the Self, Dutton, New York, 1932
F.M. Alexander, The Universal Constant in Living, Dutton, New York, 1941

Other Books
Wilfred Barlow, M.D., The Alexander Technique, Healing Arts Press, Vermont, 1973
Goddard Binkley, The Expanding Self, STAT Books, Great Britain, 1993
Deborah Caplan, P.T., Back Trouble, A New Approach to Prevention and Recovery, Triad Publishing Company, Florida, 1987
Walter Carrington, The Act of Living, Mornum Time Press, California, 1999
Walter Carrington, Thinking Aloud, Mornum Time Press, California, 1994
Barbara Conable, How to Learn the Alexander Technique, A Manual for Students, Andover Press, Ohio, 1995
Pedro de Alcantara, Indirect Procedures A Musician’s Guide to the Alexander Technique, Oxford University Press, Great Britain, 1997
Jane Heirich, Jerry Sontag, and Jay Schlesinger, Voice and the Alexander Technique, Mornum Time Press, Berkeley, Ca, 2005
Judith Leibowitz and Bill Connington, The Alexander Technique, Harper and Row Publishers, New York, 1990
Glynn Macdonald, The Complete Illustrated Guide to Alexander Technique, Barnes & Noble Books, New York, 1998
Rebecca Nettl-Fiol and Luc Vanier, Dance and the Alexander Technique, The University of Illinois, USA, 2011
Frank Pierce-Jones, Freedom to Change, Mornum Time Press, Berkeley, CA, 1976
Lulie Westfeldt, F. Matthias Alexander, the Man and His Work, Associated Booksellers, Connecticut, 1964

Or go to the Alexander Technique Books Listing on the American Society of The Alexander Technique Books for Purchase.

And Finally… alexandertechnique.com/books/
or call (800) 473-0620 in the United States, Internationally call (612) 824 5066