I have a Kenmore 900 series dryer Model #110.79822801. The dryer will not start, I have power (the light turns on when door is open). I have replaced the starter switch, the door switch, and the thermal fuse. The dryer is is still not starting. What next?

What did the meter indicate about the parts you replaced? You did not just blindly replace parts, did you? You are going to have to go through it with a meter and find the open switch or safety. Here are some manuals with schematics and instructions on using a meter: http://dl.dropbox.com/u/8010163/Whirlpool%20Dryers.zip
Test parts BEFORE replacing them, but it would help to know what the meter says about the ones you replaced.