1. Don’t read the sensor cleaning instructions. All of them, everywhere on the web.

Start here:
http://cleaningdigitalcameras.com/cleaning.html

There are important things to know about your Digital SLR:

1. Use a Rocket Blower:

2. I had a smudge on my sensor, some sort of grease spot that was showing up in landscapes, so I decided to use some fluid to clean the sensor. Turns out I was one of the unlucky ones who owns a sensor with an uneven coating on the AA (Anti-Aliasing) filter, and the ECLIPSE fluid reacted badly with it I think. Now I have a dark amoeba in my sky shots… sigh. More info on the potential problem.

More on sensor cleaning here, here