What’s great about the newly published “Microsoft SQL Server 2008 R2 PowerPivot Planning and Deployment” is that it is a guide that has the end-to-end architecture design of PowerPivot for Excel and PowerPivot for SharePoint including hardware requirements, topologies, and deployment planning.
If you want to know more about PowerPivot Planning and Deployment – this is the document. You can find the Microsoft SQL Server PowerPivot Planning and Deployment on SQLCAT and TechNet.
Enjoy!