Previously I've written about where to start when applying agile to your project. But not all people are happy with that since they want to read a book. Fair enough - I also started out reading books when agile cached my interest. So people I know tend to ask me what books I recommend to someone who wants o learn more. Typically they ask for a book on Scrum but that is not really what they want. They want a book to help them work better in their project.So this is my prioritized list on books to read when you want to learn more and implement agile into your project successfully. It is prioritized so if you only read one book, read the first one and then add more reading as you have time.

1. Scrum and XP from the Trenches by Henrik Kniberg. This book gives you many practical tips and tricks that works. It is also downloadable for free making it an easy pick for me. You get a good all round book for free. Even if it cost as much as all other books on this list together it would still be first place.
2. User Stories Applied by Mike Cohn. Writing good user stories will make things easier in your project. That's why you should read this book to get good depth knowledge on how to write those pesky user stories.
3. Agile Estimating and Planning by Mike Cohn. Before Scrum and XP from the Trenches reached the first position in my list I used to recommend this book before the current number two. But since Kniberg discusses this in his book I feel that the user stories book gives you more bang per buck than this book, given that you've read Kniberg's book.
4. Agile Project Management with Scrum by Ken Schwaber. This used to be my number one book on this list but even though this book gives you a lot of practical tips and tricks regarding Scrum, the current number one book is even more practical and also covers more things (like estimating/planning). Hence this book have been reduced to fourth place. It's still worth reading since it gives you a good solid Scrum education but only if you've already read the other books on this list.

Of cause there are more books on certain topics like TDD but that is not the typical question I get. So I'll leave such books for a future list. Maybe.