Read the guides here and/or other reputable places and videos.
http://www.tomshardware.com/forum/265056-29-2600k-2500k-overclocking-guide
http://www.tomshardware.com/forum/266189-29-sandy-bridge-series-ocing-cores-guide
Though I would suggest to only changing these options as you are not extreme overclocking (specific for asrock mobos):
Internal PLL Overvoltage: Enable
Turbo Boost Power Limit: Manual
Set Short Duration Power Limit: 200
Set Long Duration Power Limit: 200
Set Long Duration Maintain: 56
Core Current Limit: 200
Spread Spectrum: Disable
CPU Load Line Calibration: Level 1
Then it's just a matter of adjusting multiplier and vcore, probably start at 46 multi and vcore offset -.02. Don't go higher than 1.4v vcore or risk faster cpu degradation. I'm not suggesting to change other voltages til you are more experienced. And only OC from the bios/uefi.