Got me through the painful start,
This review is from: Essential ActionScript 3.0 (Paperback)
Colin is top man. This book got me through the first painful weeks of learning / using AS3
I just skimmed through it a year later, and realise that I now use most of the stuff in this book in my day-to-day work.
One VERY nice thing, is that he explains what the Flash plug-in DOES with your code, and in what order things happen. That is hard info to find and is more useful than it may appear. Essential, perhaps ;)