The majority of gun owners and many shooters never learned the proper way to use a gun in self defense.
The "defensive handgun" is taught by specialized schools that are designed for law enforcement agents and well-motivated citizens.
If you can afford it you should attend a school like
www.frontsight.com,
www.gunsite.com or
http://www.thunderranchinc.com. These are 3 of the most reputable ones.
I attended Frontsight several times. I found the instructors very friendly and helpful - surprisingly free of any "gung-ho" mentality. Women are encouraged to attend.
They assume only a basic understanding of your weapon - which you can get at most gun ranges.
I'd strongly reccommend "defensive handgun" training to anyone.