Since you the black editing it will be really easy for you to overclock. What I would do is just go into the bios and increase the multiplier to 25 or 26, and you will see somewhere in the bios something that says xxxxmhz (the X will be numbers) Increase/Decrease the multiplier until that reads 4000mhz. For the voltage, you can experiment. You want to deliver enough voltage for your clock without over volting it causing instabilities and or excess heat. With the 965 I'd say somewhere around 1.45 volts should be good, but I've only ever used my 955 so I can't say for sure.
Now for stability tests download this:
Run HW monitor while stress testing, at the end of your test (8-12 hours is good - the more the better) Look at the readings for your cpu temperature, If the max is below 70, you are good to go. Your minimum should be what your temperature was before you started the test, 30-40 is good for that. BSOD's don't harm your system, they just mean that you are possibly doing harm to your system (when stress testing a BSOD usually means your CPU got to 70)
While stress testing periodically check the value of your current CPU temp in hardware monitor to see what the average temperature of your cpu is under full load. That number shouldn't really be above 60, if it is it's ok, but I keep my temperature under 60, makes me feel safe.