Thanks for your reply. Yes, the modern matrix metering cameras will usually do a good job. 90% of the time, you can just use the matrix mode and trust the camera.

The light meter averages out the scene and most scenes fall into the average. However, if you want to absolutely ensure that a critical dark/bright subject turns out how you'd like, I would advise center or spot metering specifically on that subject to double check that the suggested values are in line with where you believe the subject should meter.

In challenging lighting situations where the overall scene is not averagely lit, this is where manually metering can save your photos. Sometimes you do need to take a photo of a dark subject in front of a dark background or of your new white Porsche in front of an aluminum (read highly reflective) modern building.

Once a beginner gets out there and learns through experience exactly when and in which situations the camera actually makes mistakes, then he/she will know to meter properly. He/she should ultimately be able to look upon a scene and think, "oh yeah, I can already tell the camera will overexpose the hell out of this shot. I should stop it down to compensate."