If you do not know, Overclocking is the process of making a CPU or other component run faster than it was originally intended to. In this case, the stock speed is 8 MHz. I can run it at 16 MHz as my tested maximum, though 12.000 MHz is the most stable speed. The speed can also be changed while the machine is running, with some additional modification.
The full rundown and a demonstration video (more on the way) here:
If this warrants a sticky I would not terribly mind one.