Ditto to what MTSCMike said. I took an NRA Basic Pistol Class and I felt it was money wasted. Like Mike said, you would be better off taking courses from somebody with practical experience like an ex-police officer, or someone with professional training experience. IDPA is another good way to learn. I found that being around other competitive shooters will help your skills about as much as anything. Other shooters will be able to see some of the things you are doing wrong. The guy that taught the NRA class I took did nothing more than pass the NRA instructor class enabling him to teach a course. He had no clue how to help me correct bad shooting technique.
Do not follow where the path may lead, go, instead where there is no path and leave a trail - Ralph Waldo Emerson