When you're living together, you'll want to respect your roommate's personal space, but before you move in, reach out and get in touch. It's tempting to Facebook- or Twitter-stalk prospective roomies, but bear in mind that what people put online isn't always a true picture of themselves. Your soon-to-be-roommate may be horrified that her granny tagged a photo of her wearing a bunny suit, and her little brother could have gotten into her Twitter account.
Your college will send you your roommate's contact information. Give him or her a call and have a chat. Not only is that the best way to get to know them, but it's the most efficient way to get basic decisions, like who's bringing the kegerator and who's bringing the PlayStation, out of the way.
This isn't a job interview, but you'll still want to put your best self forward in your initial phone calls and e-mails. Maintain an open mind. You may not be happy with the idea of sharing a room with someone who has different political, social or religious views than you, but part of the point of college it to broaden your perspective by living with people who are different. Think of it this way: If you're freaking out about your roommate's political party/religion/diet/favorite band, they're probably freaking out about yours, too.