Czesc!
Pulses per rev = it depends on the car, the simplest way to be sure that the number you've entered is correct is to check RPMs showed by MPGuino if they corresponding to the tachometer. Basically it means how many injector pulses your engine have per one rev.
After you enter everything you should calibrate it anyway. Just check MPGuino numbers with the pump and correct settings. It's very easy. But remember to check VSS pulses first. You may use GPS speedo to check if speed on MPGuino corresponds to GPS. That's the most accurate IMHO. Then you may calibrate uSec/Gal settings.
One more thing. I'm sure 500us inj delay will be good. But it has to be entered using settings screen, regardless default settings, you need to confirm that. You shouldn't leave this field empty.