The P5K Pro uses the American Megatrends BIOS, which I am very familiar with. It is a tabbed BIOS that is organized very well. Settings are in logical places where they are easily found, and all of the overclocking settings are on one page.
On the Main BIOS menu, we set the date/time, see out recognized drives, and under System Information, we can see the BIOS version. On the Advanced BIOS menu, we have most of the relevant system settings, under JumperFree Configuration are all of the overclocking settings.
In the JumperFree menu, besides the main overclock settings, there are a lot of other nice overclocking tweaks.
In the Power BIOS menu, we mainly find the Hardware Monitor, where Intel Q-fan is enabled. Q-fan helps keep our CPU (and chassis fans if enabled) nice and quiet. Also here is Intel's SpeedStep, which keeps your CPU running at x6 multiplier when not under a load, to save power.
The Boot BIOS menu contains our Boot Device Priority, with Floppy as the default. If a clean install, you'll want to set your optical drive as the first boot device, if not, your boot drive will hold that position. In the Tools BIOS menu, we find Asus EZ Flash 2, Asus' utility to flash the BIOS with a thumb drive. We also find Asus OC Profile, where we can save two successful overclock settings.
Finally, the Exit Menu, where we exit the BIOS if we have forgotten which "F" keys to use.