On regular TV, CSPAN may cover it, Fox News, CNN, and MSNBC will as well. This applies to about 5 minutes before launch to about 5 minutes after. If CSPAN covers it I watch them, since they always shut up and let NASA talk.
I usually put Fox on the TV, since they have enough sense to know that they don't know what they are talking about so usually shut up during that period.
CNN and MSNBC have too many people who think they know what they are talking about, so don't shut up long enough.
Of course if you have NASA TV on your cable or Satellite TV, that's always preferred.
For the latest news, look on the NASA site, or check out the STS-127 PreLaunch topic right here in this forum.