An interesting new book about WLS administration was released in September 2011: "Oracle Weblogic Server 11gR1 PS2: Administration Essentials", written by Michel Schildmeijer and published by Packt Publishing.
The following chapters are covered in the book:
Chapter 1: Oracle WebLogic: Your First Step into the Middleware World!
Chapter 2: The Beginning: Planning and Installation
Chapter 3: Oracle WebLogic Software Installed; What's Next?
Chapter 4: Getting in Control: Operation Basics
Chapter 5: Managed Servers and the Node Manager
Chapter 6: Deploy Your Applications in Oracle WebLogic
Chapter 7: Connecting to the Outside World: JDBC and JMS
Chapter 8: Making your WebLogic Mission-Critical: Clustering
Chapter 9: The Heart of Oracle WebLogic Server: The JVM
Chapter 10: What if Something Goes Wrong?
Chapter 11: Configuring and Analyzing Logging
Chapter 12: Keeping your WebLogic Secure: Security and Protection
Chapter 13: WLST: Makes an Administrator's Life Easier
After reading this book, you'll have a clear insight in the WebLogic architecture and the most used features. The book is illustrated with a lot of screenshots, schemes and examples, so that makes it easy to read it.
If you don't have any experience with WebLogic, or just a basic knowledge and you want to know more about it, then this book is really a must.
The author wrote his book based on version 10.3.3. In version 10.3.4, 2 new interesting data source features were introduced: GridLink Data Source and Multi Data Source. These features are thus not discussed in the book. I wouldn't blame the author for that, because it is well known that IT related books are rapidly outdated...