To take a screenshot in Mac OS X is easy, and you have more then one way of doing it.
You can use one of the following methods to take a screenshot in Mac OS X:
Command + Shift 3
This takes a screenshot of the hole desktop, and it will save it directly to the desktop.
The file name will look somthing like this: Screen Shot 2013-03-12 at 18.51.25
Command + Shift 4
This takes a screenshot of a select an area, and save it directly to the desktop
Click Command+Shift+4 and drag the mouse to highlight the area you’d like to take a screenshot of. Then let go of the mouse to make the screenshot.
Press Command+Shift+4 and hit Spacebar.
The cross will turn into a camera so you can a take screenshot of a open Window.
Tips: By adding Control to the start of either of these sequences saves the image to the clipboard instead of to a permanent file.Your screenshot can then be pasted straight into any application compatible with the usual paste command (Command + V).