How Do You Recover From A Network Outage?

Recently, I experienced a network outage at a building I do contract work for. I had a number of horrible issues to deal with that I won’t go into here. I wanted to get some opinions and thoughts on people that have either dealt with an outage (as a result of a storm or some other electrical issue). I want to get their story on how they went about troubleshooting the problem. I have (almost) completely recovered the network in question, but I want to be more proactive should this occur again.