Good day. The American Heart Association has changed some of the CPR steps. Here is your refresher (I have to adhere to these changes [though somewhat stupid] since I'm an instructor and must keep it uniform):

Adults:
-Call 9-1-1 or have a bystander call while,
-Check for response from victim. If no response, roll onto back and remove obstructing clothing.
-Kneel as close to person as possible.
-Place heel of one hand in the center of their chest, between the nipples, then put other hand ontop while interlocking your fingers.
-Be sure your shoulders are roughly above the center of their chest, lock elbows, and pivot at hip to prevent arm fatigue.
-Perform 30 chest compressions at a rate of 100/min or slightly faster (Bee Gee's "Staying Alive" is a good pace) pushing 1.5-2 inches into the chest.
-If you are CPR qualified, proceed to,
-Check for breathing by placing ear close to mouth to listen and feel while also looking parallel along the ground at their chest for any signs of chest rising and falling.
-If not breathing, perform head-tilt chin lift, pinch nose, take breath, seal your mouth around theirs, give 1-second breath, pause, another 1-second breath.
-If bystander is around, ask for them to perform chest compressions as to prevent fatigue. If not, keep performing 30 more chest compressions and 2 1-second breaths until medical personnel arrive.

Won't bother with child/infant CPR.

Disclaimer: Reading this does not make you CPR qualified. To be qualified you must attend a CPR class. Do not attempt to perform CPR if another is more qualified and do not attempt to be a hero.