About Photography have a detailed look at taking care of your lenses, from a digital SLR point of view, explaining how best to change them, protect them and clean them.

“I’ve noticed that some photographers have far more trouble with dust on digital sensors than others. In part this seems to be due to camera differences, and in general CMOS sensors have seemed to give fewer problems than CCD devices. This could reflect differences in electrostatic build-up on the two types. How well the mirror physically seals the sensor may also be important, as well as heating effects in different areas of the camera during use which could cause air currents. But even photographers using the same camera model find marked differences, and my hunch is that it may be down to how we change lenses.”

Website: About Photography - Lens Care: Cleaning and Changing Lenses