This is a compilation of reference sites for FBML and FBJS developers.
If you add to the thread I’ll compile them all into this post for easy reference.
Facebook Reference Site for Developers
http://developers.facebook.com/
thanks i have not seen resources of facebook all in one place but i think another good place as a developer is -official developers forum
http://forum.developers.facebook.net/
(they say .net is temporary and will change it .com later)
Good things about there
you have atleast similar people who understand your language-but most of them will just listen to you and may not be able to help you 
)
I have seen some official people answering some question there now
problems
Very few experts there.Sometime question like ‘does xyz do this?’ are also not answered
Plus problem with facebook platform is it tends to change too often
what was working on 2009 was not working on start of 2010 and what was working on start of 2010 is not working now…
and i strange things i find about it is they totally deprecate things esp function voilating software development basic principles
(the older code should always work,i have seen php 3 tags such as $VAR_HTTP_POST[‘NAME’] even working till now though php6 has already released …)
Another suggestions:
If you are planning to buy book to learn,donot buy books not published in 2010-The older books will only work to get theoritical knowlegde but codes of those book may not work now which will fraustrate you only…esp way the feeds are posted,notification etc are much changed now…)