A friend has a P4 3.2E Prescott (1Mg Cache) in a Abit AI 7 Motherboard, he has watercooling, he wants to know what sort of overclock he could expect and how to achieve it.
He will just have to dive in to see the limit of the cooling, processor, RAM and motherboard (remember to lock down the PCI and AGP bus). Overall, the Prescotts typically are good for about 400 MHz above factory clock.
With regard to how, there are plenty of guides out there on Intel overclocking. Generally you slowly start increasing the FSB and test for stability in between bumps.