If you have Mac OSX, it's easy to use the built-in key commands for grabbing a screen.

1.  Open the file you want to use in a screenshot.  

2.  On your keyboard, press Command (Apple) and Shift and 4 at the SAME time.

3.  The pointer turns into a bull's eye (small cross hairs).

4.  Drag a box around the part of the image you want to use by clicking on the right mouse button.

5. When you release the right button, the screen is captured and saved on your desktop. Most likely the image will be called "picture 1"

7. Insert the picture using the same steps as you have used to insert other images on Google pages. (Remember the image is on your desktop.)

This information was gathered from: http://docs.info.apple.com/article.html?path=Mac/10.4/en/cdb_winkeys.html and http://eduscapes.com/tap/topic7.htm

Print Screen on Windows PC

1.  Open the file or webpage you want to use in a screenshot.

2.  On your keyboard, press the "Alt" key and "Print Screen" at the same time.  This will copy the image to the clipboard.

3.  Open PowerPoint. 

4.  Create a new show with a blank slide.

5. Right-click on the blank slide choose paste.

6.  Click once on the image that is pasted on the slide so that you can access the picture formatting toolbar.

 7.  Use the crop tool (the 2 intertwined L's) to get rid of any unnecessary parts of your image.

8.  Right-click on the image and choose "save as picture".  Then save the picture to your key drive or the desktop of your computer.

9.  Insert the image using the same steps you have used to insert other images on Google Pages.