Keys from PC to MAC

1. Force Quit
Command + Option + Esc 
2. Copy and paste
Command + C/V 
3. Right click
Hold down the Control key while clicking on something.
4. Take screen shots
Hit Command + Shift + 3. Command + Shift + 4 lets you choose a particular section of the screen to clip. 
5. Quit the application
Closing a window in OS X doesn't actually close the app. To do that, you must select Quit from its menu or hit Command + Q. 
6. Show Desktop
Command + F3
7. Restore
After upgrade from Mavericks to Yosemite for iMac, can restore to the factory mode (Yosemite) by pressing Power+ option at the same time.
8. Bootcamp
Install windows 7, has the error "setup was unable to create a new system partition ... ", after remove another external usb disk and move windows 7 usb to another usb port, issue fixed.
9.
Command + Option + D show or hide the Doc
10.
Command + Option +Escape to bring up "Force Quit Applications"
11.
ctrl-shift-右上角CD弹出键，按完屏幕就关了
12.
Make a MAC not hibernate

Disable the auto hibernation and set standbydelay to a bigger value (seconds)

sudo pmset -a hibernatemode 0

sudo pmset -a autopoweroff 0
sudo pmset standbydelay 10800000

Press Ctrl+Shit+Eject to turn off the screen
13.
Lock screen
a. Security & Privacy -> Require Password Immediately
b. Mission Control -> Hot Corners -> Start Screen Server

14.
Command + M: minimize the windows
Command + Delete: delete the file/folder
Option (when starting): select disk