Having other books by Scot Hillier, I had high expectations for the book Professional Business Connectivity Services in SharePoint 2010and it blew those away. I teach SharePoint 2010 development and have found that one of the more challenging subjects to find details on. This book covers every single aspect of Business Connectivity Services (BCS) in SharePoint 2010. It starts out with a good discussion explaining the need and how it addresses the common challenges we face. It then goes into the details of how to implement and use custom BCS solutions using SharePoint Designer 2010.
Scot and Brad then go on to show you how to connect BCS solutions with Office 2010 as well as how to build custom solutions that are deployed to Office 2010. I had no idea SharePoint Workspace 2010 had a extensibility story! Finally they go into a deep walkthrough on building custom solutions using the .NET Assembly Connector & custom connectors. All in all, this is a fantastic resource I'd highly recommend to everyone doing SharePoint development.