There may be a topic on this already. If there is can a mod please lock this thread??
The best way to learn ActionScript is by... getting a book!! A book is useful as you do not have bookmark a page/look through the entire tutorial to find what you want.
Here is a few good books on ActionScript 3. [url]http://www.amazon.com/Flash-ActionScript-Dummies-Doug-Sahlin/sim/0764508318/2[/url] [url]http://my.safaribooksonline.com/book/programming/actionscript/0596526946[url]
I wouldn't recommend the "Dummies" books. They are written quickly and poorly.
The second book is more an advanced reference book for this book.
Which is probably the best book you can get and is part of the adobe developer library. They have a second version of it but it isn't that much different, but is adapted to flash cs5.