F. M Alexander published four books in his life time. I recommend that beginners read the third book: (Several editions are available.)
Alexander Technique Lessons and workshops in Cincinnati and the Tri-State area with Claire Rechnitzer
The American Society For the Alexander Technique is the largest professional association of certified Alexander Technique teachers in the United States.
Though best experienced with a teacher, there are plenty of Alexander Technique books and websites with worthwhile food-for-thought and information on the history, development and application of the Alexander Technique. Several books are available to borrow from The Public Library of Cincinnati and Hamilton County.
Alexander Technique is wonderful though admittedly difficult to describe — which is probably why Mimi and Eunice creator Nina Paley says she hasn’t given up on Alexander Technique though “some of its most vocal advocates have their heads up their asses”.