How do I have an adult relationship with my parent?

[GringoRingo]

A friend of this mentioned this to me. How do I have terms with my mother in which she respects that I am an adult and I can make my own decisions. Due to economic circumstances, I am now living in my family two family home as my mother's tenant. She has always been a very religious zealot when it comes to cohabitation and has told tenants that she doesn't want cohabitation going on in the apartment. When I lived here with my now ex wife it was okay because we were married. But now that I am dating again, a steady girlfriend, my mother is becoming a problem. If I was just a tenant, or if I was gay, and she tried to enforce her moral majority stuff on me, I could probably sue her. She tried to send the cops after a tenant's daughter who had her boyfriend stay the night at the apartment but the police just talked her out of her complaint. My mother is one of those New England Puritans that still thinks that For Unlawful Carnal Knowledge is still enforcable. "They did absolutely nothing," she said to me. "And I could hear them laugh as I put down the phone."
In this recession, I am underemployed, trying to scrape by on part time work and establishing my own business. It would be more affordable to stay in the family duplex but the cost of my zealous mother far outweighs the savings on the family rate on the rent.
I am looking for another place to live, a studio or one bedroom apartment. In the mean time, are there any books on how to deal with a parent as an adult child and how to explain to my mother that I have my own life, that I am not a teenager anymore and she really needs to mind her own business while I look for a new place to live?