I would like to re-introduce one of my favorite videos for teaching the various techniques that accompany CPR.  This technique is quite simple in theory; the First Aider gives compressions, in the right location, at the right pace, at the right time, and doesn’t stop until more professional help arrives.
This video comes to us in thanks to The British Heart Foundation.  While some of the information is more specific to our friends across the pond, in the United Kingdom.  The skill set is the exact same.  If you should find someone who is unresponsive and not breathing, Call EMS 9-1-1, and start compressions, pushing at least 2 inches down on an adult chest.  Pushing on the centre of the chest, approximately on the armpit line.  Your compressions should be done to the rate of 100 per minute, or as the video shows, to the infamous Bee Gee’s song, “Stayin’ Alive”.