There are several locations that developers need to visit when starting out with Flex. Visit these to quickly get started:

1. Flex.org - The single location for everything Flex. We are working on a major update the Flex.org site but this single page of links has a ton of value. Listings of the top blogs, urls for all Flex downloads, Links to Support, Lists and other goodness.

2. Flex Start Page in Flex Builder ( HELP > FLEX START PAGE )This screen was designed to provide the basics for anyone getting started using Flex. It includes “How Flex Works”, Samples, and Tutorials and Help. Here are the jewels:
a. Component Explorer - I still use this when I need a snippet of MXML for a specific component. It is handy and easy to use. You can see component working and the code that created then. Copy, Paste, Next!
b. Flex Style Explorer - There is now a link to the Flex Style Explorer. This app is invaluable for learning the details of skinning. Simply select the component you want to style, edit the properties and CSS is generated. Copy, Paste, Next!

3. Discussion Lists and Forums:
a. FlexCoders - This discussion list is the heart and soul of Flex. All the best developers frequent this list and many engineers are there. Joining FlexCoders is a rite of passage for anyone learning Flex. The list will flood your inbox so be ready, but when you have a question this is the first place to go. Search the archives of FlexCoders first, 99% of the time the answer has already been discussed.
b. FlexComponents - This discussion list is for developers writing components to extend Flex. The list was started after the component developer summit to kick start extending Flex with new components.
c. Adobe Support Forums - The forums are very handy for getting specifics on product details. There are categories for Flex Builder and Data Services so it is a bit more organized than FlexCoders or raw discussion lists. Many of the Flex engineers monitor and participate in these forums.

4. Flex Developer Center - There are fresh articles on Flex here and there are always new articles being posted to this section of the Adobe.com website.

5. Flex Cookbook - The Flex Cookbook is a place to get code and examples for Flex. The site is a mega-wiki to add articles and code from developers. It is a great resource and is growing very fast.

I am often suprised that many people do not know about these great resources for learning flex.
Thanks,
Karthick