First time overclocking here!

Hello, it's my first time attempting to overclock. I'm looking to overclock my CPU to gain higher framerate in DayZ (ArmA 2 mod) as I have heard ArmA 2 is VERY CPU dependent, even more so than your GPU.

I just got a gtx 660 yesterday and STILL have troubles maxing out ArmA 2 whilst I have a buddy with a 500 series gtx card (which is nowhere near as good as mine) and he has no problem maxing out the game. Although he does have a 4.5ghz intel processor.

I included link to my motherboard in the specs below because the motherboard mentions it being unlocked and turbo boost and stuff and I'm not quite sure but I think that has to do with overclocking?

Anyways, I'd love to OC my CPU as higher as possible w/o fuckin my *** up! xD

-Thanks,
Mark

Specs:
CPU: AMD Athlon II 640 X4 3.0GHz Quad-Core
GPU: ZOTAC GeForce GTX 660 2GB 192-bit GDDR5
Motherboard: ASUS M4A88TD-V EVO/USB3
Memory: 4G G.SKILL Ripjaws DDR3 1600
PSU: Cooler Master GX Series 750w
HDD: 500GB Samsung 7200 RPM