Flash Help
Adobe Flash CS3 Professional Books
Printed editions of the in-product Help are available for purchase in the Adobe Store, at www.adobe.com/go/store. You can also find books published by Adobe publishing partners in the Adobe Store.
A printed workflow guide is included with all Adobe Creative Suite® 3 products, and stand-alone Adobe products may include a printed getting started guide.
The main advantage of having such printed help / book is that You can check information You need without looking at Your monitor. Let Your eye rest for a while. Maybe it is faster to read whole 500 pages documentation on Your screen instead of printing it and then reading, but second choice is much more healthier.
Buying books is also advised. It is not the popular way of learning but it is still a good way.