Video tutorials:
Getting started with ActionScript 3.0 video
http://www.adobe.com/designcenter/video_workshop/?id=vid0130
Creating a Document class using ActionScript 3.0
http://www.adobe.com/designcenter/video_workshop/?id=vid0129
Creating interactive content for mobile devices
http://www.adobe.com/designcenter/video_workshop/?id=vid0267
Other Tutorials:
Flash 8 Best Practices
http://www.adobe.com/devnet/flash/articles/flash8_bestpractices.html
Migrating from Flash 8 to Flash CS3 Professional
http://www.adobe.com/designcenter/flash/articles/flacs3_migration.html