After having made the switch to AS3 about a year ago I have to admit it was a huge pain for me to upgrade from AS2. And in the end learning AS3 really will make your life easier. And note this is coming from someone with a design background so I’m not some super-genius computer nerd who has been programming in basic. It is possible for non-coders designers to learn AS3.
Developers may have a tough time to learn, and to designers, it seems nearly impossible to start and learn this new powerful language. If you are totally new to actionscript 3 and willing to learn the new language. The best advice I can give is to just start creating a project in AS3 and figure it out as you go. Just reading the book is not enough because you will just glaze over it and have to look it up again. So just jump in and do it using the resources from mouseup.me.
In mouseup.me will provide very useful materials to start learning AS3 and all the good reference about ActionScript 3. They’re definitely a great help over the last few days of AS3 development as I’ve referred to them constantly.