This is a beginner's video from Microsoft about creating a PowerPoint presentation.
Pictures are great to use in PowerPoint presentations, however, using them can be a bit tricky. Here's a good overview from a Microsoft blog about using pictures in PowerPoint, including where to find them, and how to give credit where credit is due.
http://blogs.msdn.com/b/mvpawardprogram/archive/2012/04/23/pictures-in-powerpoint.aspx