Microsoft has put together a series of free, short, training videos to help you using photos in PowerPoint.
"Next time you're putting together a presentation, you try adding one. You insert a photo right where you want it, but the photo fills up the whole slide--no room for even one bullet point. You narrow the photo by dragging its "handles" with your mouse. The face looks like a person in a funhouse mirror--all blurry and distorted. What to do?," said PowerPoint team blog.
Lesson 1: deals almost exclusively with adding and manipulating photos in PowerPoint. You'll learn the basics--how to insert, crop, and align them; then you'll move on to the fancier stuff--how to add styles and effects, and my favorite--how to reduce the overall size (as in megabytes) of your photographs so you can sidestep the inbox bouncer when you send off your presentation.
To start, go to the PowerPoint Skills Builder page embedded below: