A wonderful person (Kameusagi) works hard at trying to keep up with what anime is showing when on TV (including cable): Anime on TV
He used to be able to get the information by feeds automatically but for some reason the stations shut it off and now he does a lot by hand.
He has list associated with the site (Anime on TV list
) where he reminds people the listings have been updated and list members give the heads up on changes. (And some side discussion on anime occasionally too.)