My commute is about 6 miles each way, and while I haven't commuted to classes yet, I have commuted to work (which is on campus) since mid-May. Usually I ride 2-3 days a week, but I'm trying to do more, just gotta get my rear out of bed a touch earlier. As far as other options, I could drive myself or hitch a ride with one of the three other guys living at my place.
As far as I know, theft isn't a widespread problem. I see tons of bikes locked up with cable locks (and just around the top tube or front wheel at that) that I could probably break with my hands, or at the most a pair of wire cutters. But, bikes that aren't locked get taken. Some people (an ex-coworker for example) would take unlocked bikes just to get around and then put them in the rack where he was going.
My favorite part of riding my bike to campus is that its actually faster than going by car because the parking area I use (because its free) is on the edge of campus and even if I drove in and then biked - its still faster to get where I'm going by bike.