It’s online the Flex cookbook beta in the Adobe Developer Center.
I’m a big fan of the cookbooks since I first bought the PHP cookbook and later Python cookbook. It’s probably the most simple way to learn with real examples of common problems.

As written in the Flex cookbok beta site, the in the Flex cookbook you can:
– Find solutions to your Flex-related problems.
– Publish solutions you have created for the greater Flex community.
– Comment on solutions created by others.
– Opt for a chance to have your solution published by O’Reilly.

I hope it will grow up with more and more contents!