I have not found any books dedicated to Report Builder.
I just started reading SQL Server 2008 Reporting Services by Brian Larson. It has 20 pages covering Report Builder. The book states, "Report Builder enables us to quickly build a table report." May more pages are not needed.
These 20 pages cover:
- Report Builder Basic
- Creating a table layout report
- A matrix layout, which is similar to a pivot table
- Chart report
The book does not discuss the new features in Report Builder 3.0, such as maps.