I assume the guy before you was working from an engineered riser diagram. (for a 25 story building I hope so!) You should have no problems following the diagram, but operationally, and in terms of connection, they should all have instructions with them, which may, or may not be modified by who ever designed the system. If I were you, I'd get to know that person very well, hopefully it isn't the guy who's leaving.
Wiring diagrams like this will tell you typical connections:
http://www.greateralarm.com/gain/gainpdfs/est/ESTSIGACC1-MCC1-CC2-MCC2SignalModulesDataSheet.pdf Most of the companies who make this stuff offer training, But Edwards just got bought by GE, and thier sites are a scrambled egg right now.
I think the best advice here, that you can get, is to make sure you over-size the boxes and conduits. Ring out and lable all the wire well. As I hope your company isn't going to leave you alone to do this....
