Mouse and Keyboard Shortcuts
In addition to the navigation methods you've probably used (left mouse button to advance to the next slide, Backspace key to back up to the previous slide, Esc to end the current slide show), PowerPoint also supports a wide variety of mouse and keyboard shortcuts:
To advance from one slide to another, or perform the next animation on the current slide, you can click the left mouse buttonbut you can also press Enter, N (for Next), page down, right arrow, down arrow, or the spacebar. You can also right-click the screen during a presentation and choose Next.
To move to the previous slide, or activate the preceding animation on the current slide, you can press Backspacebut you can also try P (for Previous), page up, left arrow, or the up arrow. Or you can right-click the screen and choose Previous.
To end a presentation, in addition to the Esc key, you can right-click and choose End Show.
An almost-complete list of navigation controls is available by right-clicking the screen during a presentation and choosing Help, by pressing F1, or by referring to the Help topic "Slide Show Controls." Most of the controls are obscure, but a few might be worth memorizing:
B (for Black) or pressing the period key toggles between displaying a black screen and showing the current slide
Similarly, W (for white) or pressing the comma key toggles a white screen
Tab cycles among all the hyperlinks on a slide
The black- and white-screen options are useful when you're giving a slide show and you come to a point where you want to talk without the help of slides. Clearing the contents of the screen allows your audience to focus on you without being distracted by the contents of the last slide
This doesn't appear to be documented anywhere, but pressing the Home key during a presentation returns you to the first slide. Similarly, pressing the End key sends you to the final slide.