Links: SharePoint V3: Performance, Configuring Caching

Microsoft TechNet: Additional performance and capacity planning factors (Office SharePoint Server)
http://technet2.microsoft.com/Office/en-us/library/9f3cfe3f-01b5-406e-8615-04735ae422861033.mspx?mfr=true

Microsoft Office Online: Configure object cache settings
http://office.microsoft.com/en-us/sharepointserver/HA101577831033.aspx

MSDN: Object Caching
http://msdn2.microsoft.com/en-US/library/aa622758.aspx