If you want your room to be clean you need to start with putting things right in your head.
You should accept some rules.
Firstly, you should stop accumulating things.
You should get rid of things you don't use or may be you could offer them to people they need.
Everything must have its place that you should remember.
After using something, remember return it back.
Try cleaning your apartment at least 15 minutes a day and you can see the results of it in the near future.
I read this rules named the flylady method in a magazine.
This method pretend to be the best way to organize life of housewives.
I hope that this rules will help me to keep my desk and my closet clean forever :)