Ok, Don't worry about going wrong, most motherboards will reset if something goes wrong.
Generaly the easiest hassle free way to overclock is it increase the FSB of the CPU, just slowly increase it in increments of 3-4, and depending on the temperature increase, increase at higher increments if suitable. You won't want to be going any deeper in the world of overclocking without a Aftermarket Heat Sink, you can pick up a decent one for £15, $20.
If cooling remains ok, you may wan't to lower the CPU Multiplier, and then increase the FSB more to get a higher clock. Once your happy with a speed leave a game running, or use Prime Dual or Orthos to test your CPU under load for a few hours to check for system stability.
Post your system temps, and i'll advise from there. It'll be tommorow though, im tired.