This kind of self-taught learning is a never-ending process, just as the continuing medical education of a physician is supposed to be. By the time you have pursued it for a few years, you will probably know as much if not more than I do, especially as to how to continue the process to your own best advantage.
My main concern here is with people who are just starting on this long road to knowledge of themselves. I think they can benefit from a guide with more experience, be it myself or some other mentor, of which you will encounter any number willing to be of help on the Internet.
For those entirely new to this dangerous yet treatable, commonplace yet mostly unrecognized, undiagnosed, and untreated disease--where do you start?
It is my personal prejudice that the best place to start is not with a web site, of which there exist so many so extensive that they may confuse more than inform. I suggest starting with an old-fashioned tool--a book!
Of course, I do not mean a thousand-page, five-pound medical reference book such as the classic Principles of Sleep Medicine. Not even doctors really "read" through such compendious tomes--they just consult sections on specific issues and questions as they come up.
I mean a short, simple, well-illustrated book written with the clarity of a work meant to communicate with the general public. I mean also one that covers the basics of sleep physiology and terminology as well as the specifics of sleep apnea.
There exist a number of these to choose among. I will not pretend to familiarity with all, or even most. For years, my favorite has been Phantom of the Night, written by T. Scott Johnson, MD, and Jerry Halberstadt (NewTech Publications, 1996), which can be obtained through their website at http://www.newtech.pub/phantom/ , also a good Internet source of information on sleep and its disorders, especially sleep apnea.