don't OC unless you have something other than stock CPU cooler.
i recommend the hyper 212 evo if your on a budget. if not then the Corsair H100.
I have no idea how to OC Ivy Bridge, but I know how to OC my sandy bridge. they change every generation all the tricks and tips. so I can't help you there.
also, use Msi Afterburner... I find it to be the best.