Collecting loose change is an easy way to raise funds that does not require a lot of organization, preparation or advertisement ahead of time. Choose several places in heavily used areas like cafeterias and the school library and set up stands with documents outlining the cause and a large receptacle to accept students' loose change. A quarter doesn't seem like much money, but those coins add up. Each campus will have its own set of rules regarding when and where you can set up, so check with the student government or administration before attempting this fundraiser.
Ice cream socials can raise money at any time of year on a college campus. During the winter months, hold the social inside, either in an auditorium or a cafeteria in a central location. During spring and fall, these events are best held outside in a central square. Order the ice cream in bulk to lower your overhead costs. Set a price for each cup or cone and let the students serve themselves. Be sure to advertise this event well in advance with fliers and announcements, so people know to come.
For a more formal approach, silent auctions are often used to bring in money for organizations. Use a well-known student event night and rent space at the venue. Ask various shops and restaurants to donate meals, goods or services for your cause. Sometimes they'll give these to organizations for the promotion and other times they'll offer the goodies at a discounted rate. As students mill around, they can bid on anything from a nice dinner out to a ski vacation. Again, this fundraiser requires advertisement ahead of time to be truly successful.