positional astronomy - What is the Northernmost Latitude of Saturn?

To add to the other answers, if you were in a place where Saturn could be directly above, make sure you get there just over an hour and a half early.

Now; do you need to be there when Saturn is directly overhead or when the light from Saturn is directly overhead?

The closest Saturn gets to earth is approximately 1,200,000,000 km (750,000,000 miles), light takes 1 second to travel 300,000 km therefore the light from Saturn would take a minimum of 4000 light seconds (1,200,000,000 / 300,000 = 4000) 4000 seconds = 1.11 hours. So you are seeing Saturn where it was just over an hour before. This could increase to over 1 1/2 hours depending on the distance between Earth and Saturn at the time (max approx 1,700,000,000 km).