Jofm5, there are special devices called Colorimeters ( for example) (
LaCie Blue Eye Pro Review )) to correctly calibrate monitors as
five says a good starting point is to set the brightness level at around the around 120 cd/mē, the contrast at about 50% and the RGB levels should also be set up but vary considerably from monitor to monitor. obviously it depends on the individual monitor as to the exact figures. Larger TN based panels should be avoided due to the relatively poor viewing angles giving a brightness shift across the screen when viewing from a fixed position.