Charlotte to Chicago flights?

I'm looking to fly from Charlotte, NC to Chicago, IL during the first full week of February. Where should I look for the best deals on flights? I'm trying to spend as little as possible, as my budget for this trip is not very big. Any tips or advice will be greatly appreciated.

I live in Charlotte also and I can't imagine flights from Charlotte to Chicago will be that expensive with American Airlines in February. That being said, you could try the usual things like Orbitz or as another poster mention Hopper.