Hi Larry,

Basically you don't need to do anything until you see dust spots on your digital files. It will only be noticeable in light areas like the sky. The way to tell if it's sensor dust is that you'll see the exact spot pattern on all your images.

Common sense is the way to start out. Vacuum the inside of your camera bags and change lenses as infrequently as possible.

If you do get dust on your sensor, you can try using Dust Off with the mirror raised. Make sure to keep the can upright so it doesn't spray liquid. Anything more serious would require one of the many sensor cleaning kits, which require actually touching the sensor with a special tool, or sending the camera in to be cleaned.