Hi photo folks!

Looks to me it is normal thing to clean a camera inside time to time. I have my Canon 400d a  bit over the year, only cleaning I did is "dusting" with a blower. I had no problem sofar untill reasantly I could not remove a dust anymore. I di not "dig" into a camera I send it to the Canon repair service. They can not remove a dirt from a sensor so they want to replace a sensor. Cost me a same as buy a new Canon 400d body. No question I will buy a new camera. But how to go clean it and protect a camera in a future I have little idea. 
Please tell me how you clean your gear and how often you think it is needed to do so.
Any input greatly thanked...
seeya  Tunde

( I am changing my lens very offten. Always turn a camera downwards when I attached a lens to it. Always do this in a wind free area. I prepair a lens before hand by place it on a table rear end sitting on a rear cover loose unsrewed, so all I do is lift up a lens and attach to the camera. For a swapped lens allready a cover waiting ready so straight ways a lens goes on the rear cover.)