The following settings have worked well on the Asrock 990FX Fatality mobo and some other models also, so they might work for you.
Generally speaking it is easier to get a good, stable, high overclock using the the CPU multiplier instead of having to mess with the FSB frequency and then adjust everything else to try and compensate. Either however seems to result in essentially the same maximum stable CPU frequency, IME.
Disable the following: (Each mobo maker uses their own names for these features or settings so your's may be different)
Turbo Core Technology
Application Power management
Cool & Quiet
Core C6 mode
CPU Thermal Throttle - make sure you have sufficient cooling or do NOT disable this feature - Set CPU cooling fan speed to 100%
Set RAM freequency to 1600 or 1866 MHz. until you see where the CPU limitations are
Increase RAM default voltage by .05v, i.e. 1.50V DDR3 RAM would increase to 1.55v.
Vcore set to 1.437v to start - make sure P95 testing or video games stay below 61C per AMD
Start from 4.4 GHz. using the settings below and run P95 stress test if you want true stability. Increase in .5x increments until you find the max stable frequency. CPU temp can increase with frequency even if you don't increase the voltages.
Set CPU NB = 1.325v
HT = 1.25v (This seems to be important for most people)
2400 or 2600 Mhz. NB frequency - either is fine
2600 MHz. HT frequency - default
Depending on your mobo you want to either disable "LLC" or use the setting that holds the vcore closest to the set voltage when under load. This will take some careful testing to see what the vcore does under load using OCCT or some other program to monitor and record vcore and core temps when stress testing under load. Make sure you are using core temps, not the thermister CPU temp reading which is typically 10C-25C higher and of no value.
The Vishera CPUs are the first and only CPUs that I have ever tested where too much vcore makes them UNSTABLE even when they are not running excessively hot. There seems to be a balance required between the CPU NB voltage and vcore that doesn't exist on the Phenom II CPUs where you can basically increase the vcore for improved stability as long as the CPU doesn't run excessively hot. You can't do this on the Vishera CPUs that I have tested. Once you exceed the optimal CPU NB and vcore combo, the CPU becomes unstable.
You may find less vcore and more CPU NB voltage works best for your CPU/mobo/RAM but these are good starting points for most people.
As AMD advises OVERCLOCKING voids your warranty. I can not and do not take ANY responsibility for your use of the info. I have provided which is based on my testing and that of other AMD enthusiasts. Overclocking comes with potential risks so make sure you understand and accept those risks before overclocking your CPU/APU.