When I started doing this photography thing more seriously a few years ago, I learned early on that knowing your camera inside and out is essential. I realized that wasting time fiddling with buttons or navigating menus looking for a particular setting was the best way to miss the moment and NOT get the shot that I wanted.

Yeah, you could take the easy way out and just shoot in Auto mode all the time, but that just means that the settings will be for the type of image that the camera thinks you are trying to capture, which is not always the right configuration. This is why, for example, so many photos show silhouettes when the sun was behind you or the image of people in motion is blurry because it was getting dark outside.

In order to get the best picture, it is very important to know your camera so well that you can change any setting without even thinking about it. I don't mean that you should know exactly what values to use for each setting, but you should be able to get to those settings easily. Being able to get an idea of the right values for a particular scene comes from years of experimenting, and even after that it's an ongoing learning experience. Besides just going out and shooting a lot to practice (which is not always possible), make sure you RTFM (read the friggin' manual) . If you know your camera you will be able to do things like increase the exposure to avoid a back-lit subject looking like a silhouette, change the white-balance to make a sunset appear redder before the sun goes down, or get the right look before your model loses patience.

Play around with the camera. The great thing about digital is that you can shoot as much as you want. Even at the highest resolution you have an almost endless supply of "film". Just keep practicing, play with the settings to see what happens, and delete what you don't want... then rinse and repeat.