Im the opposite of Winston, I think classes are a great idea. The intro classes will allow you to teach your camera, the intermediate will persuade you to stop shooting the typical beginner shots, (shallow dof shots of flowers, etc.) and the more advanced classes will challenge you to explore your own photography and what it means to you, and why you do it. He is right, many teachers will push you one way, telling you there is only one way to get a perfect shot, but you have to mind that, but not exactly follow it if you know what I mean.
Im not sure about those classes you linked us, maybe check out some classes at the local college if you are old enough?