These are a few links for those who haven’t migrated from AS2 to AS3 yet. Feel free to edit it and expand it as much as you want.

Adobe’s guide. Use it only when you think “where the hell is this AS2 stuff I’ve always used“
http://livedocs.adobe.com/flex/2/langref/migration.html

This is a pdf to boost your morale and see how as3 is not that different from as2.
http://www.adobe.com/devnet/actionscript/articles/as3_migration_cookbook/as3_migration_cookbook.pdf (PDF)

A tutorial to get started on the basics of AS3 (using FlashCS3):
http://www.senocular.com/flash/tutorials/as3withflashcs3/

Grant’s skinner workshop. A little bit more detailed/difficult than previous links.
http://gskinner.com/talks/as3workshop/

Worth a look through is also Kirupa’s ‘Tip of the day’, good to search through when you come up against problems with AS3:
http://www.kirupa.com/forum/showthread.php?t=223798

I hope that’s enough to start.

For almost anything else you also have:
http://www.kirupa.com/developer/flash/index.htm#ActionScript_Basics

And of course, you can ask us anything you need.
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