OSX Shortcut Keys For Screenshot
COMMAND+SHIFT=3 ... Will grab entire screen to a pdf file.
COMMAND+CTRL+SHIFT+3 ... Will grab entire screen to clip board for cut&paste into email.
COMMAND+SHIFT+4 ... Will then turn your pointer to a camera lense icon, select the region you wish to have a screenshot of, then it will copy that to a pdf file.
COMMAND+CTRL+SHIFT+4 ... Will do the same thing, except put the screenshot to clip board for emailing.
And for a little fun and a good laugh go here.