12V 7 segment LED display

I went for a non-MOSFET as P type mosfets seem to be about 10x more expensive and rare in a TO92 package (what I have space for) - hoping it will work.

Figure 1 shows a 50R resistor going from gate to GND.... What value should i use and would it go to GND or 12v? Thanks for pointing me in the right direction.