When you have chosen roommates and you picked a place to live it is a good idea to come up with some ground rules that everyone agrees to live by. This might be things such as chores. Having a revolving list of who is responsible for what makes the work easier to bare. You also want to talk about financial obligations and when each person is to pay and how. It is also the time to talk about guests and what each of your expectations are and how often it is acceptable to have people. Once everyone has an understanding of what the rules are it will allow you to live in harmony.