basic cleaning can be done by setting to sensor clean mode, then using your blower & blow the dust away. Do it in an air-con room.
Most pple are paranoid about dusts & wants the professionals to clean the sensor. I find it a waste of money if you don't try the above method 1st.
but if yours is a consumer digicam, then no choice, gotta send in. But I doubt the dusts will affect much on it.