First off, college getting in the way is not an excuse. I have full-time courses, work 32 hours a week, and have a GF who is extremely demanding of my time, and I still find time to do a half-marathon training program. You're talking maybe an hour a day three or four days a week, including time to change clothes and shower, so it's only an excuse because you're letting it be one.
Second, depending on your current running ability, find something like a couch-to-5k training schedule (here's one:
http://www.coolrunning.com/engine/2/2_3/181.shtml). Do it. It's only 3 days a week to get you up to 3 miles.
Third, my personal suggestion is not to do it on a treadmill, because treadmills are fucking boring. If your roads or weather are shit, you may not have much choice, but I definitely would not have been able to stick to my program on a treadmill. Also, for road running, I suggest trying to do it without music. I used to think music helped me run, but I tried without for safety (so I could hear cars coming) and found I actually wanted to go longer without.
Fourth, it may be easier if you find a race you want to do so you have an exact goal to start working towards while you build up the habit. Doesn't have to be (and really shouldn't be) a marathon, maybe a 5k fun run or something.