google is the best, but what i do is join forums.
PHP/mysql ... phpfreaks.com/forums, sitepoint.com/forums/, forums.devshed.com
Flash ... board.flashkit.com/board/
CSS ...
www.designerstalk.com/forums - the designers on this site are cocky/dickheads but they're good. if you can get past that its a great site, a lot of the designers do CSS coding for big sites.
I think forums are the best, cause it'll keep you up with all the changes and allow you to ask more specific questions on why something works and is not working.