Certain video cards have the capability to output video through "s-video and DVI" if your tv is capable of recieving these connections, it's as easy as that.. Then Enable the Video card to output through that line.
TV-out on most graphics card means RCA composite video (Yellow Cable). This is not of high quality, but will work fine. Newer graphics cards have DVI out and if your TV has DVI input or HDMI input, you can connect your graphics card DVI out to you TV's HDMI using this cable.