The Alexander Technique, A Skill for Life, by Pedro de Alcantara is one of the best introductory books on the technique. It’s a bit shorter and deeper than most starter books. Students have found used copies on eBay.
If you’ve already covered the basics, here are two books that might be enlightening.
2. An Examined Life is a long interview with F.M. Alexander’s niece Marjorie Barlow, a well known teacher in her own right. This is a very thoughtful exploration of the principals of the work, the history of the technique, and what it was like to grow up in the UK in the last century.
3. Thinking Aloud, by Walter Carrington is a serious of short talks for his Alexander Technique teacher trainees, but it’s appropriate for all readers. It’s very pithy, easy to read, and full of wisdom.
The latter two books are available from Mornum Time Press, a small publisher of Alexander Technique themed book. You can also find these books on the usual online mega providers.
Looking for something outside the Alexander Technique bubble that also outlines a coherent pathway for ease and alignment? Ideokinesis, featuring the work of Andre Bernard will stimulate your visual imagination and change your relationship to uprightness.