In order to best view the images the way they truly are and the way they will appear once printed, it is highly recommended that you calibrate your monitor. This page lists the three most common ways of calibrating your monitor plus a way to do it manually yourself.
While the truest and most accurate way to calibrate your monitor is to use a colorimeter (a physical device that reads the actual color values produced by your monitor), below are some online resources to help you calibrate your monitor which should closely approximate the truest view.
If you don't have a colorimeter (most people do not) the next best thing is to download a monitor calibration software program such as this one:
On Windows 7, go to Start > Control Panel > Appearance and Personalization > Display > Calibrate Color. Then open that program which will walk you through how to get a ROUGH approximation of a calibrated screen.