The author of this website is Overeaters Anonymous, Inc. (corporate author). As for the date of publication, it says at the bottom of the website 1998-2011... APA asks for the latest date, so use 2011.
I used A.A.'s official website for one citation, and listed it thusly:
Alcoholics Anonymous World Services, Inc.
(2011). Historical Data: The Birth of A.A. and its growth in U.S./Canada.
Retrieved July 9, 2011, from Alcoholics Anonymous:
http://www.aa.org/subpage.cfm?page=288
Alcoholics Anonymous World Services, Inc. is the corporate author
2011 is the year the page was last updated
Historical Data: The Birth of A.A. and its growth in U.S./Canada was the web page from the site where I took my quote
Retrieved July 9, 2011 was the date I accessed the info (duh)
Alcoholics Anonymous is the name of the website
http://www.aa.org/subpage.cfm?page=288 is the direct link to the page I cited
Hope this helps!
Robert