How to Take a Screen Shot

first, find what you want to take a screen shot of such as... an age of mythology time-line (i am the blue line and i won). 

Step 1:

then, press the key labeled prt scrn which is all the way at the top next to f12 and above insert.

Step 2:

then go to a program such as paint and click paste and... ITS A SCREEN SHOT!!!