Keyboard Shortcuts for OS X on the Macintosh:

Note that Command is the little apple key.

 

Editing:

Command X Cut to clipboard
Command C Copy to clipboard
Command V Paste from Clipboard
Command A Select all
Shift- navigation key Select Text

Finder Navigation

Arrows Select adjacent files
Tab, or Shift Tab Cycle to next, previous folder alphabetically
   
Command Up Arrow Go to the parent folder
Command Down Arrow Open the selected folder
Command Click the title text Pops up a menu of ALL the parent folders
Option click close box Close all the windows
   
Option drag file Copy file to new location
Command Option drag file Make a shortcut to file
Command Delete Delete selected file
   
Command Shift N Make a new folder
Command N New window for Home Directory
Command Shift A Open Applications
Command Shift U Open Utilities
Command Shift Q Log Out
Command Shift Y Run Stickies

Maintenance

Command Option at startup Rebuild Desktop
Command Option P R at startup Zap PRAM
Command Option Shift Delete at startup Don't use internal Hard drive
Mouse button at startup Eject CD
Apple S at startup Single user mode to run disk diagnostics

Nifty Things

Command Shift 3 Screen shot to file
Command Shift 4 Selection shot to file
Command Shift Control 3 Screen shot to clipboard
Command Shift Control 4 Selection to clipboard
Command Option Power Key (or eject key) Sleep
Command Option Shift Power Key Shutdown
Command Tab Next application
Command Shift Tab Previous application
--Expose for Panther  
F9 Show all windows
F10 Show windows for current program
F11 Show Desktop

Generic in program shortcuts

Command S Save File
Command P Print current document
Command W Close window
Command Option W Close all windows
Command Q Quit Program