I used to look up television programming on sites like tvguide.com and tv.yahoo.com — services which show you a grid of what's on the schedule. And those free sites were fine for what they provided. However, for a measly twelve bucks a year, one can subscribe to DigiGuide, which is a more sophisticated, multi-featured way of finding out what's on and what's going to be on.
DigiGuide was originally a British-only service and that's where the company is still based. But they've extended to the U.S. (and elsewhere) and seem to cover even the smallest UHF stations I can receive. You download their software, tell it what channels you receive and then it downloads the latest program info for those channels, compiling it into a highly-searchable database. Very neat, very handy. I've spotted a lot of shows I wanted to watch that I might otherwise have missed.
You can download a 30-day trial version over at www.digiguide.com. If it doesn't help you out, delete it before the month is up. If it does, send 'em twelve smackers for a year's subscription. End of tip.