I think this could be a good place for us to consolidate all of our learning resources in one place. There are so many on the web that it is difficult to keep up with them all.
Also, it would be great to have an area for people that are not ready to post their questions to the flexcoders list with all of the advanced users lurking (and laughing maniacally??) as we/I post really stupid questions. If everyone else reading it is learning as well it always seems to take the edge off a bit!
Flex 2 Language Reference http://livedocs.adobe.com/flex/2/langref/index.html
This link goes to the reference docs for the entire Flex 2 framework. It is extremely helpful for learning the framework and the properties and methods for objects within the framework.
Flex 2 Style Explorer http://examples.adobe.com/flex2/consulting/styleexplorer/Flex2Style...
This link provides a Flex application that will allow you to quickly and easily create style sheet definitions, and see the changes in real time, on real flex components. This is very helpful for quickly making something look good, if you don't have a user experience designer handy.
Flex 2 Component Explorer http://examples.adobe.com/flex2/inproduct/sdk/explorer/explorer.html
This link provides a Flex application that will allow you to browse different kinds of Flex components. This helps you become familiar with the different components of the framework.
QuietlyScheming Chart Explorer http://demo.quietlyscheming.com/ChartSampler/app.html
This has got to be the best example for Flex charting on the internet. You can see lots of different chart customizations, play with different data effects, and it has complete source code to achieve all of these capabilities. This one is HIGHLY recommended.