Living with somebody you do not know is very difficult. Not only because you may have never seen them, but also because they may have different customs and habits that could become main problem while living together. Have you thought about which are the characteristics a good roommate should have?
Being a roommate is not easy neither for one or other. We all, as human, are different and becoming part of a new little "family" can be a disaster if you do not try to make it work.
Respect, It is not only about property(which is very important too), it is also about personal life. Having a Roommate does not mean you will have to share your whole life of course, as long as it does not involve the other one.
Patience, because at first you are knowing your roommate, you are learning the way they are and which are their likes and dislikes, we have to keep in mind the other one is in the same situation as you are. Things may not work at first, you may discuss and disagree not one but many times.
To be talkative and expressive is important too because if you do not say the way you feel about others actions, they will never know it and so far a "disaster" will be around.
Personally, I had the opportunity to share an apartment with 5 girls for 3 months and a half, and then with other 7 for one month and I had never seen them before but when we were told to live together, based on my own experience, I have to say Respect, Patience and Expressiveness are a must while living with others. It will not only let you live with a "family", but also make great friends.