Some links you may find useful...
General information about the Alexander Technique
STAT is the main professional body for Alexander Technique Teachers in the UK. This site is an excellent starting point for learning more about FM Alexander and his discoveries, about the teaching of the Technique and about research into its uses.
This is a site maintained by Robert Rickover in Canada and is an excellent source of general information about the Technique.
AmSAT is the largest professional body for teachers of the Alexander Technique in the United States.
Mouritz specialises in books about the Alexander Technique.
A list of properly conducted clinical trials and research papers on the Technique.
This is on a site called My Ergonomic Chair and it's a neat collections of, well - lots of reasons to try the AT. It also gives links to research supporting these.
There's masses of stuff about the Technique to explore on YouTube. The range and variety are such that it's best to watch quite a few different different practictioners doing different things in order to get a feel for what happens in lessons.
Of course what none of these things can do is show you how great the Alexander Technique can make you feel.
For that you need to experience it for yourself!