A couple of quick web based display calibrations I use are DisplayCalibration.com and Online Monitor Test.

If your computer and monitor supports DVI connections (pictured on left), make sure you hook it up that way.

Adjust the Phase and Clock

If you only have VGA available you’ll need to adjust the clock and phase before moving onto contrast and brightness. This is typical done by pressing the “Auto” button your monitor. The 1:1 pixel mapping screen from Online Monitor Test is a great screen to use to let your monitor adjust the clock and phase automatically. This is not necessary when using the DVI input as it is digital.

Adjust Brightness and Contrast

Go to DisplayCalibration.com and select “Brightness and Contrast”. Use the top two bars to adjust the contrast. Set the contrast as high as you can and still see a distinction between the left and right side. Some monitors will not display the top bar correctly, so use second bar if this is the case. Use the bottom bar to adjust your brightness. Set your brightness to its lowest setting that still allows you to see a difference between the left and right side of the black bar.