I've done a bit of research on it myself (my mother is into it.) Like every other pseudoscientific/pseudoreligous philosophy, it just chooses a really complex way to explain something really simple. It's all about color balances, how the eye moves (hence why curves and softer colors are given high standing), and just plain how people react to their envirornment. Even if you don't believe in it, many Feng Shui books do have good decorating ideas in them (just avoid the astrology parts). There is no reason to pay someone to practice Feng Shui in your home, when simple common sense and a little basic pschology will suffice.

It is prounounced Fung Shwee by the way, just to stay on topic.