Not ingame but like on ur desktop

On your keyboard there should be a button on the top that says 'Print Scrn' and on the bottom it says 'SysRq' which will take a picture of the desktop if your using a pc.

How do you get to see the pictures?

One way I do is I would open up a drawing or image manipulation software and paste it.
You cant just paste it anywhere so if your in a hurry I suggest Windows Paint.

I dont have paint i used to have it now i dont D:

http://www.gimp.org/
There you go.

if you use windows 7 there's a crop screen button or something like that, when you crop it you are able to save it etc

^
snipping tool

indeed - Start -> Accessories -> Snipping tool

I don't see any snipping tool in my lappy