You might be able to save some time by having Scheedule [0] add your school. It was created at UIUC, and I've found that it works very well. I know it provides some other functionality beyond class scheduling (via FB integration), but most people I know just use it to plan their schedule.
Edit: It looks like schools are added based on a voting/popularity system, which wasn't what I was expecting.
Edit 2: Classwhole [1] is another UIUC creation that's been open sourced [2] and might work for you.