Yes, exactly what Andy said! Lots of turkeys (especially turkey breasts sold separately) and chickens are already "enhanced" with a salt solution, which means you can't brine them or they'll be inedible.
I've only hosted thanksgiving once, but I used the same recipe as Andy, and I brined my turkey overnight as well. Well, I actually had to improvise a little on the recipe, as I realized that a few of the cartons of vegetable stock that I bought were out-of-date. I substituted maybe 2 quarts of apple cider. It was fantastic.
I also used Alton Brown's roasting method, as described in the recipe, which was awesome.
One thing to consider is that the drippings from a brined turkey are going to saltier than normal. To make life easier on myself I made a make-ahead gravy
that was absolutely delicious, and can be made up to 3 days in advance. The only change I made to the recipe was to use fresh thyme.