First things first. DON'T PANIC! We have no time for that silliness. When the herd of undead are headed your way, running around like a headless chicken only serves to make a bad situation worse.
Deal with the problem at hand and get to a safe location. Now - let's see what is in our emergency kit.
Supplies: The first thing you need is THE PLAN (tm/c). I'm not talking about the plan in your head - this should be written down. The apocalypse isn't going to wait for you to be standing there so we need to make sure that your employees know what is going on. What is on your emergency plan might be specific to your business, but there are a few things that should be on every plan: