Looking for a wiring diagram for a fire alarm system, and/or help in wiring one.

You have not given us enough information. There are any number of systems available. What is the building occupancy?

Fire alarm installations are typically a licensed profession.

I'm sorry, even if I had the answers my conscience prevents me from helping someone who has to ask a question such as this in such a way.

Do you really want to feel your way through something as critical as a fire alarm?

Or are you talking about simply smoke detectors in a residential home?