Keynote is Apple's own presentation application. Like PowerPoint, it allows you to put on impressive presentations, but faster and with better end results.
Using keyboard shortcuts is the best way for beginners to become more efficient Mac users. Close? Open? Minimize? There is a shortcut for that.
The Macbook Air is a thin yet powerful laptop that is great for Mac users who wants to take their work with them at all times. You will love it!
If you keep your Mac in a public place like an office or a university, you should definitely add a password to your screensaver. It only takes a minute!