Pic18F4520

I'm new to MCU's and Pics and totally confused. I'm trying to create a 125kHz squarewave for my RFID reader using a pic as well as other operations. But i need a 4Mhz clock that i'm using a 14 stage binary counter to divide up to get the 125khz. I know that the PIC has some kind of internal clock, how can you get it to output 4Mhz. I'm using a PIC18F4520. Please help me out, thanks.

What crystal are you using?

You can use internal oscillator and have it's output divided by 4 on OC2 pin. Configure it for 4MHz with 4xPLL. You can read about it in section 2.6 and elsewhere in 18f4520 datasheet.