first thing:
get into your bios and familiarize yourself with it, so you know how to adjust the ram speed, cpu clock, ram voltage, cpu voltage, and ht multiplier (also ldt multiplier)
to overclock that opty:
lower the ht multiplier to at least 4 (it will be stock at 5), once you get external clock above 250, you need to drop it to 3. as a matter of fact, just drop it to 3 to begin with, that will ensure that it causes no instability.
lower your ram speed to the second lowest setting that is availible in your bios.
make sure the ram has the proper voltage and timings.
begin to increase the external cpu clock in increments of 10-15, and use prime95 or (i prefer) orthos to test for stability, at the BARE MINIMUM a couple of hours. this is just the preliminary stability test, when you reach a good clock, you can test it for 8 hours or so. if it fails the test, raise the voltage in the smallest increment possible and test again. if it still fails, raise the voltage another increment and test.
for no reason, unless you have a whopper of an overclock should you raise the voltage above, say...1.475 (at the moment...when you know a little more, a little more voltage is okay).
try these steps and post back if you have questions.