I had a hard time understanding exposure and aperture so what I did, selected one spot, put the camera on a tripod, wrote down all possible combinations of the exposure and aperture setting my camera would offer and shot pictures of same frame with these settings. Check later on on monitor to select what is the best and fathom more into that setting with respect to the lighting situation or overall composition of the shot. Read photography books and try to follow their techniques, like rule of third that I learnt while shooting sunrise and sunset from one of the photography book. Visit sites like pbase.com and try to analyse the shot/picture from the exif data, if possible. It helped a bit. Try to use the settings of your camera with respect to the lighting and metering options. I learnt this one exactly same as I learnt exposure and aperture settings. The performance usually varies from camera to camera..