My BMW just recently started running rough

My BMW just recently started running rough. It started a few days after I got an oil change but that may just be a coincidence. The car starts without a problem but when I accelerate it seems as if the gas flow is having interruption and thus makes the car "jerky" and it is also cutting off at red lights but I have been able to restart is so far. I am going to change the spark plugs and fuel filter today but I have a couple questions. Can you tell me where the fuel filter is on my car and also what is the gap setting for the spark plugs. Any help or advice you can give me will be very much appreciated because if I can't get this fixed, I am going to lose my job.