Make sure you are working within a web.

On the menu bar click on Format, and then Background.

On the Page Properties dialogue box, click in the Background picture box.

Click on Select a file on your computer.

Browse on the computer system to find a suitable background image.

The image file would probably have a JPG, GIF, WMF or BMP extension. Click OK.

An interesting white and yellow background graphic was found. 

Next the graphic file must be saved within the web.

To save the background graphic within the Images folder

Click on Save.  The Save Embedded Files dialogue box opens.  Click on Change Folder to put the background graphic in the Graphics folder.  Click OK.

In the Change Folder click OK.

In the Save Embedded Files box click OK.  Note that the GIF image is now in the Images file.

The background looks more interesting with the yellow variegated background. 

Care in the choice of background picture is needed so that it does not overwhelm the main source of information on the page.

Note that if you are using a FrontPage Theme your own background image is replaced with the Theme image.