This book gives a very good introduction to the concepts underlying the RESTful way to design Web Services and explains in details the benefits of a Resource Oriented Architecture. The main issue that I noticed is that the examples are kind of outdated. But, it is actually pretty cool to see how much the web evolved in the past 10 years.
If you come across a cheap copy of this book, I would recommend to read the chapters that are about the general principles of the resource oriented architecture and the examples of how to design a well thought web service. The authors are going in great details about why the type of architecture they are advising for makes sense and compare it with other possible designs. It is extremely useful to understand the value of these principles.