Space Shuttle Atlantis will be the final shuttle to launch from Cape Canaveral.
Launch time is 8:26am PST July 8th, 2011. The launch window extends for 10 minutes. Coverage will being several hours before hand on NASA TV [link] Coverage of pre-launch activities is already broadcasting.
Information about the mission can be found here: [link]
If you don't have time to watch the whole thing, allow yourself about 20 minutes and start watching at 8:15am PST. This will get you the final minutes before launch and the trip into orbit (about 8 minutes long). It is amazing to think about everything that has gone into making this sort of thing possible. This is the end of an era, an historic moment.