well at
Actionscript.org Macromedia Flash Resources and Tutorials there is an article called "going from AS 2.0 to 3.0".
There are two of them. I suggest reading them both, they helped me a lot getting into the AS 3.0 thing.
f you're searching for other tuturials about AS 2.0 or so you could visit
kirupa.com - Shocked Resource for Making Designers better Developers!, or
Model Zone - Portfolio of Professional Model Maker Joe Dunaway....I don't know if there are good tut's that can help you there but have a look!