Here you can learn many things about your system from shortcuts to manipulation. Things are going to be put here in no particular order as I think of them or as people ask me about them.
Quick Note - the apple key (next to the spacebar) is also called the command key. A dash between 2 or more keys means press them at the same time.
Quick Keys
Command-C Copy selected image or text
Command-V Paste selected image or text
Command-Q Quit current application
Command-W Close current window
Command-S Save current document
Command-Shift-3 Take a screen shot (saved on start up disk as a pict file)
Command-Shift-/ or Command-? Bring up the MacOS Help box
Option-Command-Escape Force quit current application (if it freezes)
Control-Command-Power Restart the computer (if it freezes)
Buttons to Hold Down at Start-up
C Start up from system software on a CD.
Shift Turn off all extensions (and control panels)
Command-Option Rebuild the desktop file
Error Codes
If you have problems with your computer, do a self diagnosis of the error messages with this program.