If you're using a desktop computer with windows... which you probably are..
There'll be a Print Screen/ Prnt Scrn button twoards the upper right part of your keyboard.
When you want to take a picture push that button.
From there open paint or antoher photo editing softare system and go up to Edit than select paste.
Save this file as whatever you like.
You can than upload this picture to photobucket, imageshack, or tinypic.