LCD with regular TV tends to look rather poor. Try out a DVD, especially after calibration. My dad has a Samsung LCD and regular TV looks kind of crappy, but as soon as you fire up a DVD or put it on an HD channel, the picture is amazingly clear.
You calibrate exactly the same way as with any other display - with the remote
Then you'll need a disc like Digital Video Essentials, Avia or Home Theater Tune Up.