My guide should give you a rundown on viewing shuttle launches. Many have found it helpful:
http://www.launchphotography.com/Shuttle_Launch_Viewing.html
Titusville is the place to go other than buying tickets which can get you closer. Tickets for the Dec. 6 launch would go on sale about six weeks beforehand, and they sell out in about two minutes. There is a link in my guide to the kennedyspacecenter.com site where the tickets would be sold. There is an email signup on that website to be alerted via an ad when tickets are about to go on sale.
Right now, the schedule is tight for Dec. 6 but it is still on track. You should note that there is a window from Dec. 6 to 12 that that mission (STS-122) must launch in before being postponed to at least Dec. 30 though more likely after the New Year holiday.
This site gives up to date launch dates most of the time, and is the best one to bookmark:
http://www.spaceflightnow.com/tracking/
And here is the NASA/KSC launch schedule which would also show shuttle launch delays as they happen:
http://www.nasa.gov/missions/highlights/schedule.html
Keep in mind that the nasa.gov link only lists NASA launches (the space shuttle, and rockets with NASA payloads). It omits other rocket launches of which the first site has a complete listing.
As far as the sound goes, from Titusville it may not come across as the "very loud roar and crackling rumble" people may expect. You can hear it very clearly and feel it easily as well, and being 12 miles away that is amazing every time (name something else you can hear from 12 miles away). But don't expect the jaw dropping, 'drowns out everything around you' kind of noise; you would have to be with press or VIPs at the three mile mark for that

However, if you can get the causeway tickets (6.5 miles) or even visitors center tickets they sell (7.4 miles) you will get your moneys worth on this subject. It is pretty loud and powerful from there (especially the causeway). But I stress it is hard to get your hands on the causeway tickets in realtime. Tickets for the visitors center are easier, though.
Good luck and if you need any more help please ask.