Is it possible to import a picture to use as a background for a slide show? I want something specific that isn't found in the program's backgrounds or on the online library. I found the background I want from a Google search, but can't figure out if it's possible to import it to Power Point.

Yes!
First save the picture to your hard-drive. Now open Power Point and on the menu go to View and then select Master and Slide Master. This will be the tempate you create. Now go to Insert from the menu and scroll down to Picture and select From File. Select the picture you saved on your hard-drive and double click it to add it to your presentation. Now you will want to make it transparent so you can type over it. To do that, first select the picture in your presentation and then locate your picture tool-bar. If it does not show then go to menu View, Toolbars, Picture. Select the Set Transparent Color icon which looks like the eraser end of a pencil with a black right angle at the bottom left of it. Once you click on that icon then click on the picture. You should see it change. Now you are almost done. Just do a File, save as and "Save Type" as a Design Template. Once you do that, go back to View, Normal and start inserting slides. All of them will now have the picture background.

Hope that helps! I don't know about you but I am exhausted now!

From MS PowerPoint Help (Version 7.0; This is an older version)

Add or change a slide background picture

1. In slide view, on the Format menu, click Custom Background.
2. Under Background Fill, click the down arrow, and then click Picture.
3. Double-click the filename of the picture you want to use as your background.

Your exact menu pathway may differ, but the option should be in Format/"Slide View" menu list.
Picture of the "Insert Picture" tool.

I see that Georgia85 has once again beaten me to the "Reply" button. Good answer, Georgia!

Dwight, may I add something to your method? If Sarah follows your directions she will need to Apply to All from the Background box, after she has inserted all the slides she will be using. If she doesn't, only the first slide will have use the picture she adds.

And Dwight, your answer was easier I actually thought about using that as an option but decided to go with the ol' Template answer to allow her to be able to save it and use it for future presentations.

Georgia, good point and thanks for adding that.

Dwight