Mac: keyboard shortcuts

Taking Screenshot

• Capture the whole screen to clipboard:
  control + shift + command + 3


• Capture the whole screen and save it to desktop:
  shift + command + 3


• Capture part of the screen to clipboard:
  control + shift + command + 4


• Capture part of the screen and save it to desktop:
  shift + command + 4

OS

• Lock computer
  shift + control + power


• Sleep
  command + option + power

Finder

• Delete a file
  command + delete


• Open a file or directory
  command + O


• Rename a file
  enter


• Go to folder
  shift + command + G

Navigation

• Home
  fn + left arrow


• End
  fn + right arrow


• Page Up
  fn + up arrow


• Page Down
  fn + down arrow


• Switch between different applications
  command + tab


• Switch between application windows
  command + `


• Application windows
  control + down arrow


• Mission Control
  control + up arrow

Text editing

• Delete text after the cursor (in-place delete)
  fn + delete

Firefox

• Focus to address bar
  F6 -or- command + L


• Go to home page
  alt + home = fn + option + left arrow

For more keyboard shortcuts, see:
Mac keyboard shortcuts - Apple Support

If you are switching from Windows, also see:
Switch Basics: On Windows, I used to... - Apple Support