If you are getting a new tv, hopefully it is an hdtv of some sort. Those will have HDMI, DVI, or VGA, sometimes all 3, sometimes only 1. But any of those would work, with HDMI and DVI being the best.
Then you'd need a cable to run to it, DVI is likely what you are using for your monitor, so if you had a spare one of those you could use it. If not, you could order from a place like monoprice.com to pick up a DVI-DVI or a DVI-HDMI cable.
You would also need a way to get your sound to the tv. I think some of the new video cards actually have a way to do that through HDMI, but most just run a line from their sound card to whatever the line is on the tv. Usually 3.5mm to RCA.