I'm an Actionscript developer and I found the Actionscript 2.0 Bible to be fantastic. It's basically a 'How to...' reference book that lists its entries by function rather than code or class type references. If it's a comprehensive code based reference you're after, there isn't anything better than Adobe's on-line AS 2.0 and AS 3.0 references, which you should have bookmarked in your favourite browser anyway. This book's ideal for getting started in coding if you're a novice. There aren't many books of this kind on the market and this was, by far, the best one.
Ok, and now onto the new version of this book...
For your money, you get pretty much the same thing for AS 3.0 as you did for AS 2.0. It also does a very good job of explaining some of the fundamental differences between the two languages, such as the new events architecture and the display list, both of which are indispensable when coding in AS 3.0.
However, I got the strong feeling that this book was rushed to the press. There are a large number of code errors such as on page 505 where it has,
"var connection:NetConnection = new NetConnection(null);"
This will throw an error in Flash and your movie won't work. The correct code should be:
"var connection:NetConnection = new NetConnection();
This is just one of many examples throughout the book that a novice developer would find infuriating. Something that is even more infuriating is that there are a number of omissions from the book. In one case, two entire pages of code and the class file were missing from the book and the accompanying download which left an entire project useless and a waste of time.
This book does give some very useful information in a very easy to use and understandable way and it'll help you to get to grips with AS 3.0 in a very short time. But be warned. It's not properly proof-read and the editing is very sloppy. Since the life-cycle of versions of programming languages is so short, it's unlikely to be corrected so be prepared for code that doesn't work and that you'll have to check against the Adobe AS 3.0 reference, and projects that you might spend a lot of time typing in only to find out that it's impossible to make them work!
It's still the best book of its kind, but I couldn't possibly give this book more than 3 stars. You may find books from Friends of Ed more accurate and helpful but they don't really do anything like this one.
Hope this helps.