Agile Testing: A Practical Guide for Testers and Agile Teams by Lisa Crispin and Janet Gregory is a practical book is for testers who find themselves on an agile team, test and quality assurance managers in organizations transitioning to agile development, and agile teams learning how to approach testing. InfoQ presents a pdf download of Chapter 21- Key Success Factors, which is the last chapter of the book and presents 7 critical issues for successful agile testing.
Uncle Bob Martin, of Object Mentor, Inc., says of this book:
Refreshingly pragmatic. Chock-full of wisdom. Absent of dogma. This book is a gamechanger. Every software professional should read it.
You can read an overview of the book and download a chapter from this article.