Overclocking my AMD Athlon 64 3700+

I want to overclock my computer that i bought from BestBuy. I know that the bios doesnt support overclocking. I have an AMD Athlon 64 3700+ with 1 gig of ram. I'm really noob at overclocking. So if you guys can help me with overclocking using a software or something it would be great. Thank you

First thing we need to know is what kind of computer it is. If its a prebuilt from some one like HP, Sony, Compaq... then overclocking may not be an option. If its a custom built from BB (never go there so i dont know if the sell parts or not) then we need to know what motherboard your using.