Dorm Room Etiquette

Could any experienced roommates explain the simple Do's and Don'ts of dorm room etiquette?

Specifically, I want to know if keeping a beside light on to read late at night be enough to disturb my roommate. I also would appreciate any other rules-of-thumb for rooming with another person.

I know this question may seem obvious to many, and I know the answer will vary depending on who your roommate is, but I have almost no experience living with other people, so any replies would be very helpful to me!