A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
As to your buttons, you can add Next and Previous buttons via Insert | Shapes | Action Buttons.
These won't do anything in normal view, but will let you move through the presentation in Slide Show view.
As long as you don't cover them up with your images, you can put the buttons on whichever slide layout you're using ( go to View | Slide Master ). That'll let you create one set of buttons but have them appear on every slide.