I am a big fan of taking a class or taking lessons. I like taking a class if it's something completely new just to try out and see if I'm interested. If it's something I'm somewhat familiar with, but not completely sure, I'll take lessons.
Both classes and lessons will teach you what you need, and how to do the activity successfully to minimize injury and increase enjoyment. Plus, a good teach, can give you pointers and tricks to help you a long your way.