Know what your rights and obligations are.
Treat your decision to rent, and the way you act as a tenant, as you would treat a business decision. Before you rent, you want to know everything about the unit you are renting and the agreement you are making. You want it to make sense for you. You want it to work for you. You want to be comfortable in your home.
Keep written records. If you sign or create any kind of document, keep a copy for yourself. Keep paper copies of your rent payments and rent receipts. Keep copies of written notices you give the landlord about needed repairs. Make notes of when you talked to your landlord and what you talked about.
Do not let a problem go on for a long time without trying to solve it with your landlord.