See the original announcement about Flash with Drupal’s release in the Drupal news section.
Publisher’s description:
This book takes a step-by-step approach to building Flash applications for use with the Drupal Content Management System. In each chapter, you walk through the evolution of a real Flash application designed for Drupal. Every chapter builds on the previous one by presenting a more challenging feature for each additional chapter. This book is written for developers who wish to build dynamic flash applications. Although we will be using Drupal for our Content Management System, the lessons learned within this book can easily be applied to other content management systems such as Joomla or WordPress. Because of this, you are not assumed to be familiar with Drupal. Any interaction with Drupal will be described in full detail so that anyone can follow along. As for Flash, it is not necessary to be familiar with how to use Flash since that too will be covered within this book. However, it is recommended that you have some modest understanding of ActionScript and PHP since there are many code examples within this book.