Just did my first overclock yesterday on my AMD 955 BE. Went from stock 3.2ghz to 4ghz on air on the stock cooler.
I set my multiplier to 19, bus to 210 and voltage upped from 1.360 to 1.425 in the bios.
Just search your proc name and mobo name and OC you should find plenty of similar setups. Also checkout speed fan if you need a program to monitor your temps. My temps went from 39c idle to about 47c idle, and caps out at about 62c when under full load on Prime95.
Going from 3.2 to 4ghz made hardly any difference in A-10C, I maybe got another 2fps, went from 28fps to about 30 on the runway in the pit. DCS beta 4 isn't using these new machines to their potential. It only uses 1 core fully and maybe a tad on another. Im running 2 gtx470s in sli which does nothing for DCS, unlike a game like ARMA2 which will fully use both cards and all four cores.