look down... at your keyboard.
check the arrow keys, look up, you will see:
- - - home - - Page Up
-Delete - - End - - Page down
Look further up, next to F12, you will see
-Prt Scr (Print screen) - Scroll Lock - Pause -
Click the print screen button (the one next to F12)
Open paint, type Ctrl + V
and Voila
Capturing screenshots for dummies