Overclocking?

I'm a newbie,  when it comes to Overclocking...
I want to Overclock my AMD 64-bit 3000+ (( 2ghz )),  I'm aware you have to go into the BIOS,  but after that... I'm clueless;  Can someone point me in the right direction?

First: why would you need to overclock it?

Second: You change the FSB(front size bus) speed up. it's probibly default 166mhz.