Your PDA's screen can get pretty dirty, especially if you're using the handheld outdoors. The best way to clean your PDA's screen is to use a microfiber cloth, much like you would use to clean a camera lens or a pair of eye glasses. While cotton is slightly abrasive and could scratch your screen, microfiber cloths won't scratch your PDA's screen.
Air cans are not recommended because they contain a very cold liquid that could potentially damage the screen.
For long-term protection, invest in a screen protector. There are many available on the market, some of which are precut to match the size of your PDA's screen. Most of these protectors aren't very expensive, but they are very valuable in protecting your screen.
