Understanding Camera Functions

Understanding my camera seems to be my biggest obstacle at the moment. I think I have a good eye for what will make a good picture but need to understand the changeable functions of a camera in order to adjust its settings in order to create the picture I have in my mind.

I have decided that I will concentrate/study on different functions and in turn produce test images showing different variants of the functions. I will relate these findings to my own understanding of my own camera (Nikon D200)

"A camera has to make a lot of decisions when you press the shutter button. It needs to determine the brightness of the scene and the distance of subjects in order to set the camera's ISO, aperture, shutter and focus. This all happens within milliseconds."