I have found that the  document below, The Performance PM: Driving for a Faster Product (which first appeared on MSDN), is an invaluable overview of the issues many organizations need to consider when trying to improve the page load times and other performance issues. It is always difficult to squeeze the performance testing and fixes into the normal development process. In fact, it is only after PMs are assigned full-time to performance issues that many organizations are able to make headway with performance issues.

The Performance PM