As you already may know, we have a couple of forums for PowerPivot at:

• SQL Server 2008 R2 PowerPivot for Excel
• SQL Server 2008 R2 PowerPivot for SharePoint

Dave Wickert with his PowerPivotGeek.com site has also created two new sections:

• Reported Problems section which compiles the different issues concerning PowerPivot for SharePoint installations and
• Troubleshooting section which complies different Troubleshooting issues concerning PowerPivot for SharePoint installations.

Please do not forget that the all four PowerPivot for SharePoint installation guides can be found here as well.

Rob Collie has also put together:

• The Great PowerPivot FAQ

where you can see some of the key MVPs respond to some great questions concerning PowerPivot …disclosure: myself and Dave are also answering questions there 🙂

The coup de grace of course is is Dave and my downloadable Academy Live presentation which

• Academy Live: A Preview to PowerPivot Server Best Practices. 

This will definitely help jump start your PowerPivot for SharePoint geekiness.

Enjoy!