When calibrating with test tones and a meter you set your surrounds to the same loudness as your other speakers.
During a movie or music, several things affect how much sound comes from the surrounds. If the material is discrete 5.1 (Digital Dolby 5.1, DTS 5.1, multichannel SACD or DVD-A music) the amount of surround is dictated purely by the mixing engineer. It's an artistic and aesthetic choice when the material was mixed. You can't really change it much except by overriding your surround volume and going to non-calibrated levels.
If the material is stereo, you usually won't hear any surround unless your receiver has a mode for reconstructing surround from stereo. Examples are Dolby PLII and Harmon Kardon and Lexicon's Logic 7. In that case amount of surround depends on the reconstruction technology and characteristics of the stereo source. Some stereo material will produce good surround with PLII/L7, and others don't.
Pink noise is what the receiver and DVD player test tones often use. It's usually on your calibration DVD as well, along with a lot of other stuff. Read the literature or on-line documentation that comes with that.
Don't worry, it's not hard at all, once you get the hang of it. After a while you can do it without even thinking about it.
