My recommendation would be that you simplify things as much as possible to the items that make the event important and effective and then do those incredibly well.
For instance, if you are going to have an announcer and that is a big part of the event, make sure you have a good microphone and sound system that will allow everyone to hear clearly - even when you have hundreds of people in the room. Take this one step further by planning the music you will play, etc.
Success is in keeping things simple, removing unnecessary items while paying attention to detail where it matters. A coat check station (if your event is inside in the winter) is an example of something you should pay attention to and get right, while searching for weeks for the right paper to print the awards on is probably not if you catch my drift.
This is my first time having a chili cook off. My first time, but not the first for the school. Anyone have any pointers or things I should do? I'm combining the cook off with a silent auction. I have an announcer. That's about it so far. I've been gung ho for the silent auction side though.