Do the treadmills have cardio receptors on them? Use them. A BIG mistake many beginners have is pushing themselves too hard, too fast, causing them to give up. Use the technology in the machines to set yourself a limit. It may feel slow at first, but it's really the best thing for you.
If they don't have cardio receptors, it's a bit harder: you have to police yourself. Find your maximum heart rate (220-your age=HR) somewhere between 65-90% of that is the best range for you to work out in. I'm 20, and my "cardio" workout rate is 160 bpm, while my "fat burn" workout rate is 130. Yours will probably be a bit lower than that.
Once you reach your target HR, stay there for about 30-45 minutes. You need to work out at least 3x a week in order to improve at all. Make sure you're stretching too.
A few easy rules for eating (or
not eating) are: eliminate Coke/pop, cut (waaaay) down on empty calories like alcohol, chips, and ice cream, and cut way down on eating out (look at the calories on some of those meals! You probably need about 2500-3000 calories a day, and many "meals" are already 1000, easily.) Gatorade/Powerade are good after a workout, not before. "Energy bars" are usually full of calories and sweeteners, so avoid them unless you have a brand that works for you. And there is no shortcut! Pills and "special diets" are a load of crock. Healthy diet and exercise are the only real solution.
Find your favourite vegetables and fruits and keep them accessible. I know it's hard being a student and trying to cook, so foods you can eat raw are a blessing.
In the past month or so, our little fitness community here at WH has grown a lot. There are quite a few women posting their progess under this thread:
http://www.womens-health.com/boards/...eed-buddy.html
Accountability is a big thing.
And as a personal note: though I've been equipped with all this knowledge for years, I just started exercising again routinely this past Monday. Because I know how to pace myself and push myself, it's quickly become the highlight of my day. You might not lose those 30 lbs by summer, but I guarantee you will feel great about yourself if you make moderate changes to your lifestyle.