I've had experience over clocking my AMD FX-6300 CPU, so I'll help you out.
The basic concept of overclocking is trying to get the best clock speed you can, while having a reasonable voltage and temperature and stability.
For FX CPU's, your temp. should not go above 62.5° C while gaming, and 70° while stress-testing. Also, try to keep the voltage under 1.4v, but do not exceed 1.43v.
So you're starting out at 4.3 GHz, right?
Increase the clock speed in 100 MHz increments. Increase it until your computer crashes when it tries to boot.
Once that happens, increase the voltage in increments of 0.01 volts, until you can boot into Windows successfully.
Then, download Prime95. It is a CPU stress-testing program.
Do a torture test on all 4 threads. Watch your temperature. If it goes above 70° C, it's time to either lower your clockspeed, or get a better CPU cooler.
If Prime95 crashes or reports an error while running, then bump the voltage by 0.005v. Do this until Prime can run for 1 hour without crashing. If you're already at 1.4 volts, then you've reached your processor's limit. It's time to stop OC'ing.
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Keep doing all of this until you reach your desired speed.
•If you need more than 1.4v to keep your CPU stable, then your processor is at the highest it can go. CPU's vary in their ability.
•If your temperature goes above 70°, either lower the clock, or get better cooling.
•If Prime has an error, increase the voltage.
So that's my guide to overclocking.