If you are new to Flex or if you are just curious about the capabilities of Flex, the Flex Component Explorer is a great place to learn by example.   Click on a component in the list, see a working sample on the right with the code below it.

The explorer has been available for awhile but I have met several Flex developers that were unaware of its existence.

Component Explorer for Flex 2: http://examples.adobe.com/flex2/inproduct/sdk/explorer/explorer.html

Component Explorer for Flex 3: http://examples.adobe.com/flex3/componentexplorer/explorer.html

Screen shots of the Component Explorer:

 

 

 

Source : http://gregsramblings.com/2008/07/12/flex-3-component-explorer-a-must-for-flex-beginners/