SQLCat has a new article in their Building and Deploying Large Scale SQL Server Reporting Services Environments Technical Note Series.
This note provides guidance for both SQL Server 2005 and 2008 Reporting Services. The focus of this technical note is the report server catalog—the underlying databases that provide the metadata (parameters, snapshots, history, and so on) that are used by Reporting Services to provide your reports.
Read the entire article here.