Cafeteria meal plan is actually pretty sweet.
First of all: breakfast. You usually got your standard fare of crap, but I think the standard eggs that every cafeteria serves are a respectable choice and most cafeterias have hard-boiled eggs. Snatch up like 5 hard boiled eggs and you can eat them cold as snacks. Also, the usual banana/orange/apple trio of cheap fruit is available for the taking. At my school the good fruit went fast and by dinner time there was only two brown bananas keeping a moldy orange company, so swipe a good 4 or 5 pieces of fruit early on and you will be thankful
Second: lunch. Most schools have the standard salad bar and 90% of the time will have green peppers, tomatoes and broccoli. My typical strategy was to go on a 3-day rotating schedule between these three where I would just fill up a whole plate and bang that down with a little vinegar on top. A little weird? Yes, but I figure that when you combine that with the 4 pieces of fruit you stole at breakfast that's pretty good for your fruits and veggies for the day. Also, most schools have either a sandwich line or cold cuts just laid out. Cold cut turkey and roast beef is a solid bet for protein. Don't be afraid to be obnoxious and take a solid half pound plus a little later. If they have the big leafy lettuce for sandwiches grab a couple of those, roll a couple slices of turkey inside and you have a great snack for your 4 o'clock class.
Third: dinner. It is a 50/50 shot the cafeteria will put out a respectable dinner. Sometimes you get the dry pork loin which, while not too appetizing, can be shoveled in quickly and washed down with water for a solid dose of protein. Sometimes you get the grilled chicken drowned in some random sauce that can be mostly dabbed off and winds up tasting pretty good. Sometimes you get sloppy joe. Can't all be winners. Peanut butter sandwiches washed down with milk are great for post-workout calories and if your school has a vegetarian line, which many do, you can usually find some solid veggies or clean carbs.
All in all, the cafeteria really ain't too bad; bring ziploc freezer baggies and bag extra when they have the good stuff so you're okay when they toss out those random meals every once in a while where there is absolutely nothing of nutritional value.
For stuff you can cook in the microwave:
1.) Plain oatmeal + some combination of splenda, cinnamon, bananas (free from the caf) and natural apple-sauce (the kind with no sugar added). I also recommend checking out "Muscle Milk and Oats" as this is Muscle Milk protein powder pre-mixed with oatmeal. It is delicious but incredibly sweet; I would only add a half-serving in to sweeten up and add some extra protein to my plain oatmeal.
2.) Canned chicken. Some say this is a little gross; some say it smells like catfood. All would be correct. However, beggars can't be choosers and 50 grams of protein that can be eaten in 2 minutes is nothing to take lightly.
3.) Arizona Diet Green Tea. No calories, a decent amount of caffeine and you get the psychological benefits of thinking the "green tea" is giving you some sort of healthy anti-oxidant benefits that outweigh the massive splenda poisoning you may or may not get from cutting sugar out of your diet.
4.) Smart Balance Peanut Butter. Only like 30 cents more than regular and, in my opinion, tastes better. I think it tastes best refrigerated but a friend likes it room temp. To each his/her own. Spread/dip on/with bananas, celery, carrots or whatever your little heart desires.
5.) Pizza. Cuz fuck it, it's college and you can always just train a little harder the next day after eating pizza the night before.