Sensei - Teacher, it is also used for Doctor. Onore - a rough way of saying 'You'. Here's a quick and easy guide on the name attachments.
Close families use it and close friends use it.
It's used for little children. Most people stop calling each other -chan after the age of 14 or so. The usual term for respect. It can mean Mr. or Ms. It is used for strangers and people you don't know well who are more or less in the same social status.