• http://blog.flexexamples.com/ – I think is official flex development website. But, there are not info that I need.
• http://www.adobe.com/devnet/flex/ – Adobe Flex developer center
• http://opensource.adobe.com/wiki/display/flexsdk/Developer+Documentation – Flex 3 Developer Documentation.
• http://www.adobe.com/support/documentation/en/flex/ – Flex resources.
  
• http://www.petefreitag.com/item/490.cfm – A simple example of flex, should be useful.
• http://learn.adobe.com/wiki/display/Flex/1d.+RIA+Tutorial – Official flex&AIR tutorial
• http://riadiscuss.jeffmaury.com/2008/09/maven-and-flex-builder-tutorial-part-i.html – Flex builder tutorial
• http://www.beedigital.net/blog/category/tutorial/flex-tutorial/ – Good video flex tutorial, there are infos I want. example flex communicate with php and database(http://www.flashmove.com/forum/showthread.php?t=31580).
• http://www.visualbuilder.com/flex/tutorial/ – Good flex tutorial, you can became senior flex developer by 19 stages
• http://www.actionscript.org/resources/categories/Tutorials/Flash/Beginner/ – Actionscript online tutorial, also is useful in flex development.

If you know more than above links, you can share with us in following as a comment.