Microsoft Performance Resources
It is interesting how far interesting information is sometimes hidden. Looking for specific information, I found a couple of very interesting pages on the Microsoft site, which never seen before. One is Windows Performance, a resource page with links to performance-related white papers. Another is PeopleSoft & JD Edwards Whitepapers and Webcasts, including SQL tuning whitepapers with a lot of usuful info for any applications, for example: Microsoft SQL Server 2008 Tuning Tips for PeopleSoft Applications.