Monitor Calibration:
Photographs prepared for use on the Internet usually suffer from a lack of detail in the highlight and shadow areas. Especially TFT monitors can be problematic. Calibrating your monitor for brightness and contrast can improve your viewing experience (more advanced color calibration may also be needed).
If you can distinguish between all 16 distinct shades on the grayscale below, do nothing. The leftmost bar is pure white (nothing should be brighter), the rightmost bar is pure black (nothing should be darker).
To make adjustments, use the buttons on your monitor:
Now, whilst watching the grayscale, turn the brightness back down to the point where you can still just distinguish between the two rightmost and the two leftmost bars. You may not be able to achieve this fully on all monitors; try to get as close as you can. In many cases, between 90% and 100% works best for contrast and between 50% and 100% for brightness.