need help with overclocking

[gplracer]

I helped a friend build a computer and i am not familiar with overclocking on this board. The motherboard is a gigabyte GA-G31mx-s2

I see the following in the bios:

Cpu clock ratio 8x
System memory multiplier with options of: auto 3.3 4.0
Performance enhance with options of: standard, extreme and turbo.

I have DDR2 800 memory
Intel 2140 cpu

Thanks!!!