How to rent a place from Chinese without problems? (Beijing)

Hi, I am changing my job, so I'm a bit limited in finance and decided to rent a room from Chinese. Could you, please, send me an example of a good contract for rent? Should it be in Chinese or it can be in English as well? What kind of problems should I expect?
And one more question: if the owner doesn't want to register you at the police in the flat/room that you are renting (she is talking about taxes, can it be the reason?), is it a problem if she registers you in her own flat in another place and why?
Thank you very much!!