1. Make sure tha car cover is water proof. If not, when it rains, the water will become sort of trapped on the soaked cover and may damage your paint.
2. How long is it staying like that for? If it's going to be for a few months then you should change the oil and coolant just for good measure and kack up the car on it's proper points and keep it off it's tires. If not, you'll develope a nice dent on your tires from saying in place for a long time.
3. Leave the e-brake off. Just to release the tension on the braking mechanism.
4. Leave a few rat/critter traps near your car. mice or other rodents tend to like cars too and sometimes they chew through hoses or wires just for the hell of it.
5. Take a picture of it and carry that with you in your wallet. Whenever you get lonely in school, look at it, I;m sure that will bring a smile to your face.