"NLP's core idea is that an individual's thoughts, gestures and words interact to create one's perception of the world. By changing one's outlook, a person can improve his attitudes and actions. These observations can be changed by applying a variety of techniques.

NLP teaches that a person can develop successful habits by amplifying helpful behaviors and diminishing negative ones. Positive change can come when one carefully reproduces the behaviors and beliefs of successful people (called 'modeling'). It also states that all human beings have all the resources necessary for success within themselves."

"

NLP works by associating thoughts/situations with feelings. For example, if you're facing an exam & are scared, NLP would teach you to identify the feeling that will most help you through that situation (e.g. feeling positive & in control), then to associate that feeling with the exam you're scared about by remembering a time when you were positive & in control. Each time you feel bad, you think again about the time you had the good feeling & gradually you'll find the good feeling attaches itself to the situation in place of the bad one.
NLP is no more than a technique, but a very helpful one. It's worth reading a book or two about it first, then see if you can work it for yourself. If not, find somebody else who is proficient in it to help you grasp it.

If you want to learn it as a self-improvement technique, that's great. But if you are wanting to learn it as a mode of therapy . . . save your money.