According to the manual I read when taking driver's education, the driver is ideally supposed to stop when the front of his/her car is right next to the stop sign. One should not cross the white line.
It just depends. Most place anymore have a white line at the stop sign. But I was taught to pull up enough that you can look both ways before you pull out onto the road. I see too many people about 3 or 4 feet from a stop sign and they can't see both ways go onto the road.
