When overclocking, which settings would I alter?
CPU Core Voltage,
More than just that i can tell you now. Depending on what CPU you have and what the communication and cache architecture your CPU utilizes there can be upwards of 30-40 different settings to tweak just what the CPU receives. I'll go over the basics
CPU VCore: This controls the voltage the processor cores get. On older CPUs that dont have split plane power (Each section of the chip gets its own power supply and voltage), this increases or decreases voltage across the entire chip, cache and all. On newer chips that do have split plane power (starting with the first gen i7s and the Phenom I series), the Vcore option changes the amount of voltage the Execution cores get, while the cache and other parts of the chip are left alone. Without exception while overclocking you will have to increase this by some amount. Just keep in mind: Temperatures increase linearly with the clock speed, and with the square of the voltage (a spectacular example of this is with my E5300. It'll do 4ghz at 1.45v and hit ~75 degrees C. Increase the clock to 4.166ghz and i need 1.5v, which increases the load temp to over 100C)
CPU Reference Clock: This is the base clock from which the CPU, and more often than not, everything else directly connected to it, derive their clock speeds from through the use of clock multipliers and dividers. Changing this will change the CPU core speed, the cache speed (if unlinked), the memory speed, and on older systems the Northbridge speed. Nowadays changing this is more or less a moot point as you can buy CPUs that have unlocked multipliers for relatively cheap prices, but older CPUs like my Q9400 had locked multipliers, and in order to overclock it as high as i did, i had to increase the Reference clock, which in turn increased memory speeds.
CPU Ratio: This is the number by which the CPU derives its core clock speed. Basically: (Reference Clock) x (CPU Ratio) = Core clock. Using my E5300 example shown above, the 4.166ghz figure can be gotten by: 333mhz x 12.5 ratio = 4166mhz. On high end CPUs this is unlocked both ways, allowing the end user to overclock the processor simply by increasing the multiplier. On lower end and older CPUs, this is only unlocked to the smaller multipliers, or locked entirely.
Vdroop: This is supposedly an intel spec thing where the CPU voltage drops slightly while under load to reduce power consumption, but the gist of it is that while a CPU is under load, the power circuitry has to go from feeding maybe ~10 amps to 50-60 amps, which in turn causes the voltage to sag a bit. Enabling Vdroop control or whatever it is named on your board causes the motherboard's voltage controller to counteract this while the CPU is under load, often neutralizing or even overshooting while fully loaded. Lots of Vdroop is bad when overclocking, because you may be putting in one voltage, but when the CPU goes under significant load, the voltage goes from a stable level to an unstable one, crashing the computer.
If you have any more pieces of terminology that you need to learn about them, ask and I'll get around to it when i wake up.