Just my opinion:
I wouldnt overclock this CPU unless you have liquid cooling and a real need to do so. The AMD FX-8320 is a hot blooded CPU to begin with when used with stock cooler that comes with the CPU and everything that Calum stated is correct.
Also even if a motherboard supports over clocking in the BIOS features, it does not mean that the motherboard wont run into problems such as with the Voltage Regulators (VRM)'s roasting and failing. Better motherboards have a heatsink applied to the VRM's to keep them cool, however lower cost motherboards can come without them and allow for you to burn them up if you drive the CPU/Board to hard with an overclock.
Unless you have a real need to OC this CPU, I'd avoid it. For more then 99% of the people out there its plenty of processing power and usually overkill at native clock, and when a powerful video card GPU or pair of GPU's/cards are teamed up with this CPU you have one powerful system on your hands for gaming.
I haven't overclocked any of my CPU's until it was towards the end life cycle of them, when they are starting to show that they are strugging to keep up with the heavier processing demands of today vs the easier processing demands of yester-years. When a CPU is at the end of its life cycle usually around the 5 year in age mark, you can drive the old CPU harder to squeeze more processing power out of it to get say 1 or 2 more years out of it with an increase between 5% and 25% more processing power out of it depending on the overclock performed, proper cooling methods used and how hard the CPU can be driven in speed before it starts to destabilize no matter how cool you can keep it.
Just as an example, I overclocked a quadcore AMD Athlon II x4 620 which is a budget quadcore from its native 2600Mhz to 2847Mhz by increasing my FSB on my RAM from 200Mhz to 219Mhz with a 13x multiplier. My CPU is a locked CPU so I had limited over clocking abilities and the motherboard has all sorts of features to alter the settings manually to fine tune an overclock. What I found is that the system wouldnt boot at 220Mhz FSB, and booted at 219Mhz FSB but would blue screen randomly. I then worked my way down to 216Mhz FSB when it was stable, but I was getting surging in my games with FPS jumping around. When I dropped it 1Mhz to 215Mhz FSB for my Corsair DDR2 800Mhz XMS2 higher end gaming RAM which works well for over clocking, I was now at 2795Mhz vs the 2600Mhz that I started at and the system was running good and the performance gain was noticed in boot time and in games, but my CPU was now running 55 to 60C from what it use to be running at 40-45C at native clock, so this extra 195Mhz of processing speed raised my CPU temp by about 15 degrees C, and the main reason for it running so hot was because I was using a 95watt cast aluminum heatsink which was not the best heatsink for driving a CPU under an overclock condition. I then decided to go back to 200Mhz FSB and bring the CPU back to 2600Mhz because summer was around the corner and I didnt want to cook the CPU to death.
There are many methods to overclocking, and some CPUs are limited or wont take an overclock at all, and then there are others like the Intel Core 2 Duo E6600 which is a 2.4Ghz CPU that can be easily driven to 3.2Ghz or higher with proper hardware and cooling.
