You can Google for various timings for diff amounts of meat etc you put in. Pressure cooking cooks at a fraction of the normal time, becos it raises the boiling point of the water to above 100C - abt 105C. It supposes to seal in the nutrients better.
Normally for pork or beef, best you can stew. Turn the heat on high and when the cooker gives out its first loud hiss, you must turn heat down to low (like 3~4 on electric range) and then wait for it to hiss again before the pressure stabilises and the valve can be heard giving out small hisses in quick succession. Time this for 10~12 mins, and then turn off stove. Cool off to open or fast cool under running tap. You can hear a sharp collapse of the pressure inside. The meat shld be tender.
Same with others like chicken except times wil be diff - shorter. cannot steam fish in it. Good for potatoes (5 mins), red bean soup, green bean soup (12~15 mins).