One thing that might help you decide is to put your camera in auto bracket mode. You can use options of how many pictures to take, and what increment to take them in. When you hit the shutter, it will take all 3, 5, 7 or whatever you have programed in at the fstop increment specified. Later on, you can look at the photos and decide how far off the metering was, and how much is gained by X amount of under/over exposure. It is also helpful in dealing with difficult lighting situations that will not fall into a normal pattern of exposure determination. Of course, This isn't very helpful shooting fast moving subjects where you need to get the right exposure at the moment you first press the shutter.
I normally just use aperture preferred and use matrix metering. I find that digital is much more forgiving of under/over exposure than film, and post processing can produce very good images that are a couple stops off. Not a reason to be complacent, but it is nice to know you can still get good photos when exposure is not spot on. Keep in mind, I am still rather new to the digital world of photography.