What is the proper pressure setting when cutting metal with an ox-acet torch?

Here's a quick chart with normal procedure settings - http://www.nhada.com/docs/Oxygen%20and%20Acetylene%20Gas%20Pressures.pdf

I always go for rich blue flame cones on my cutting torch at work.

I think the numbers you are looking for are about 5# of acetylene and 25# of oxygen. The thing to watch is the flame. After lighting the gas, reduce the flame to the point it is not producing any soot and is not separated from the tip. Then slowly open the oxy valve to the point where you get a bright white inner flame and a bluish outer flame. Remember to give the matal a chance to heat up before applying the oxygen and hold the tip at 90 degrees to the metal. Good luck.