Hey techman,
Many Mac-Windows keyboad equivalents (including Print Screen) are give at About.com's Keyboard Equivalents (
http://macos.about.com/library/weekly/aa101601a.htm ) Page. Remember, these will be pre-OSX systems only. Were you looking for a way to Print Screen from OS X? It's jut a bit different.
Pressing Cmnd-Ctrl-Shift-3 on your OS8.x or OS9.x Mac will copy a TIFF of your screen to the clipboard. You can paste this into virually any application (word processors, image viewers, etc) to modify of print it.
You can also download shareware or freeware like Snapz Pro (
http://www.ambrosiasw.com/utilities/snapzpro/ ) to extend your abilities to do these things; but as you can see from the About.com link the list of features already built-in to the OS is already extensive.