People with more experience than I will chime in, for sure. But my recommendation is to get and read a copy of Zimmerman's book.
The Used 911 Story, 8th Edition: Peter Zimmermann: 9780963172662: Amazon.com: Books
It has a wealth of information, and people around here, although an incredibly welcoming bunch (for the most part), are understandably much more willing to help once the asker has done the easily available leg work on their own.
I can personally vouch that the answers to many of your questions will be found in this book.
Good luck in your search (and nice 914!)!