what is your TV model. what kind of audio outputs do you have available? if you don't know please provide which sound card, motherboard or the model of your PC. if you have RCA outputs you should easilt be able to connect it directly with your hdtv.
The best way to connect your PC to your HDTV is with any high speed HDMI cable, since HDMI carries both audio and video signals. This way, you get the best quality possible, and can transfer both video and audio with only one cable. Simple! However, to do this, of course, your PC will need to have an HDMI out on your video card. If yours doesn't then you will have to upgrade. Don't worry though, you can get a card to do that for less than $50 online.