I asked this same question basically, and I was linked to this youtube video;https://www.youtube.com/watch?v=MckeAmnDeTk
I have a FX 6100, and I was able to overclock to 3.9 GHz without failing to POST or blue screening or crashing. Just follow this, take down what you need to, and do what he says. You might need to do some stuff under the ADVANCED tab in the BIOS, and some stuff in the PERFORMANCE tab of the BIOS. Look through these two places to find what you need to turn off.