Remember that the perfect shot is generally not the only shot in your camera. Work the subject, get an attractive frame on it in camera, you can't change perspective later. And everything else that was said in this thread down to the polarizer which i carry religiously.
my tip would be to photograph, and photograph often. Use the camera and don't leave it in the box. Carry it with you, and photograph in all lights, situations, people, landscapes. You'd find what interests you, and understand your equipment.