It is tough to find good books on subjects like web services. The people that write on the subjects are usually writing about the current state (which is outdated by the time you buy the book) or a future state (which is usually wrong). Generally speaking, I don't buy books on web services - however, I do buy books on areas of convergence. That said, here are my recommendations:
1. Policy Based Network Management - A book by John Strassner, a Fellow at Cisco and thought leader in DEN, writes on the topic of the declarative network. The book covers basic policy models and then explores the DEN-ng policy model as an example. The book will never mention SOAP, web services or anything at the application level. It is up to the reader to draw analogies between Network Policies and Application Policies. For those that are familiar with the WS-Policy specs, you will find significant overlap between WS-Policy and PBNM (Policy Based Network Management). This book should help you understand the importance of declarative policies and their uses in application-level service networks.
2. Grid Computing - A book by Joshy Joseph and Craig Fellenstein, this book is part of the IBM 'On Demand Series'. The book covers the basics of grids, the merging of grids and web services, OGSA, OGSI and the programming model for the Globus GT3 Toolkit. This is a good book for anyone who needs a crash course in grid services. It is a high-level read - not a reference manual.