You need to sign up for a CPR class. If you are looking at entry into EMS, it should be an AHA Healthcare Provider class or ARC CPR for the professional rescuer. All of these questions are covered in the classes. The answers are slightly different depending on whether you are a bystander or an EMS responder.
Agreed. We may be able to give you the right detailed answers, but you dont/wont have the big picture.
When you take a full CPR class, you will learn such things as how to asses a patient for life-threatening injuries, how to properly protect yourself (re: liability and body fluids), how to perform proper breaths, compressions, back blows, abdominal thrusts, etc, and receive a certification.
If you are looking to find a class, check out redcross.org or americanheart.org
Good Luck!
Dan