It's the first thing you see when you get up in the morning and the last thing you see when you go to bed at night. It should be a space that really expresses you, not just a collection of random backpack kibble.
With the right paint color, some interesting fabric, cool posters, and one or two fun yet functional light fixtures, you can create a room that's perfect for your daydreaming self and may even make homework time a little easier to take.
To get started, think about what you need to make your room work for you. You may think a calendar and a desk are pretty dorky, but you have to have some place to put your work stuff, yes? And your room is a MUCH better place to get down to school business than the dining room table or the den. So figure out where you're going to put the hafta's and then feel free to play with the rest. After all, Mom and Dad are going to be much sweeter about springing for a few decorating extras if the purpose is to improve your studies. ; )