Here’s a great article from Lifehacker on how to deal with a difficult landlord. In my current position, landlord/tenant disputes are the number one type of legal issues our office sees. I think the most important aspect mentioned in the article is to put communications in writing. A writing (with a receipt showing the landlord received it) helps to clarify issues, document issues, and can provide a defensible position later. Writing everything down also means taking pictures before you move in and as you move out. Taking pictures is a great way to have proof about the condition of the apartment, particularly if the landlord alleges that the renter has damaged the property or left it dirty.
The value of the writing goes both ways. It can also protect the landlord from claims that repairs weren’t made and, in the instance of a bad tenant, the damage that was caused.