OK, here's some info on the stuff that shows up on the main screen of CPUZ (In brackets is what I have on my computer, for comparison).
Core Speed: What the clock rate is inside of your cpu. (2600 MHz)
Multiplier: The amount that the Front Side Bus is multiplied to get your Core Speed. (13)
FSB: Front Side Bus, the speed at which the CPU transfers data to other devices in the computer. (200 MHz)
Bus Speed: Pretty much the same deal as the FSB. Whenever you mention what the speed of your FSB is use the number that shows up. (800 MHz)
Cache: Superfast memory thats attached to the CPU, that makes sure that the CPU is always busy.
Hopefully that helps