Step 1: Put pressure on the wound with whatever is available to stop or slow down the flow of blood. (You are acting as a 'plug' to stop the blood from escaping. The pressure you provide will help the blood clot and stop the bleeding). You can use dressing pads from a first aid kit, a piece of heavy clothing, a tourniquet, or even a blanket to put pressure on the wound.
Step 2: Keep pressure on the wound until help arrives.
Step 3: If the bleding is severe and you see pale face and sign of dizzyness, call 911 or get someone else to do it.