Jess have we got ideas!! There is a former post on here that you may have to dig a little but I don't think you will be diapointed. Click on Foucus on Fundraising and that can get you started! You want ideas--
car wash
ask for donated books from families and sell them for $1
sell baked goods during lunch hour (may need to ask if can)
candy bars
some resturants offer a percentage of they net profit- Souper Salad is one
My brain just quit but I hope this gives you a start.