There is no substitute, absolutely NO substitute, for actual hands-on practice to correctly learn CPR skills!
This free online CPR training class shows the steps you need to take to perform when administering CPR, but without a manikin to practice on under the guidance of an experienced CPR instructor, you should not believe you can do CPR.
The American Red Cross CPR certification classes and the American Heart Association CPR certification classes are both excellent, recognized, CPR training programs that will teach you the skills you need and get you certified. Certification is a consistent way to indicate you have been taught the skills, but you still need to review them periodically - that is why the certifications are only in force for a year or two.
The Red Cross offers many types of CPR courses. They have a one-day course that covers CPR and first aid training so you receive two certifications at once. There is also a shorter CPR class just for training on CPR. An American Heart Association CPR class covers similar materials to an American Red Cross CPR class.
CPR classes can be attended at many Red Cross locations or arranged to be taught at your location. If you are in the Minneapolis, Minnesota area, a good instructor runs Active Source Training and provides CPR training to Boy Scouts and other groups.
There are many other authorized Red Cross partners that can provide you with quality CPR training - contact your local Red Cross office to find out what CPR class you might take.
An online CPR training course is great for learning the basics and building your understanding. Please don't stop there - take a CPR class, get certified, and be ready to help someone.