You can just play around with the CPU FSB and Multipliers in the BIOS to overclock the CPU not to mention RAM overclocking too.
As for video card overclocking, go to the manufacturer's site as they might offer some overclocking software more of a tweaking program. I had my Hercules Radeon 8500LE overclocked a little by using a program from Hercules website.
As XtR-R has mentioned earlier, overclocking can be quite dangerous. If your hardware is not offered sufficient cooling, they will burn thus causing the warranty to void. All overclocking are to be done at your own risk!