Since you aren't actually booking a ticket, price and availability aren't an issue. Use any flight aggregator to find options. You will still want to find reasonable connections, economy fares, and departures from Huntsville. Ask for roundtrip airfare, as the prices will be cheaper than one way + one way.
There are airline ticket bookies through Tripadvisor.com, or use any of the following:
Travel Channel is a commercial operation, so expect to find these pages full of advertising. That being said, you can also expect spectacular photography, journalist-written articles on travel to a wide variety of destinations, and some helpful advice on do's and don't's of the destination city.
A great site for hotels, restaurants, and tourist attractions is Tripadvisor.com. The site also has links to airline ticket brokers (i.e. Orbitz, Priceline, etc.). Use the forums to find insider information on attractions, travel options, restaurant reviews, and the like.
Like its parent, Wikipedia, Wikitravel is audience written, by anonymous contributors. Some of the pages are nicely fleshed-out, some are sparse at best. The site will useful for tourist hints, restaurant recommendations, and general knowledge of the city.