There are plenty of good reasons to have a PC hooked up to your TV. Maybe you have a really small place and don't have room for both a desk area and a TV area. Maybe you have a large media collection on your computer and don't want to buy a separate device to stream that media to your TV.
Maybe you're a cable cutter, or maybe your HTPC is your cable box. Maybe you'd rather game on a fully armed and operational PC instead of an eight-year-old console. Whatever the reason, you need to get the picture from your PC to your TV, and then control the PC from the couch. Since this is such a big topic, I'm splitting it into two parts. Today's guide is to discuss everything except gaming with a mouse and keyboard, and the second part is, well, that. The first part is a lot more forgiving, and the second part...may not have any good solutions.
For the purposes of this article, I'm going to assume that you want to use your living room PC for gaming and media, rather than productivity.
Getting The Picture (and The Sound)
If you just want access to the stuff on your PC, you can use DLNA or UPnP from an Xbox 360, PS3, or any of a number of other devices (although the PS3 and Xbox 360 are picky about what codecs and containers they'll accept), or even from your TV screen itself. My official recommendation is to use Plex Media Server and a Roku 3. But if you want to view your actual desktop from your TV, you have a couple of options.
The easiest way to get picture and sound from your PC to your TV is via HDMI. Why HDMI? Well, all modern HDTVs have HDMI support, and your PC should have either HDMI or DVI, which can be converted to HDMI via an inexpensive cable. If you've hooking up to a TV rather than a monitor, though, It's better to use HDMI, so you can pass digital audio over the same connection. If you do DVI to HDMI, you'll also need to pass audio to your TV or receiver--ideally via digital optical cable.
Modern graphics cards from Nvidia and AMD can output protected digital 7.1 surround sound over HDMI, including DTS-HD and Dolby TrueHD, so all the digital-to-analog conversion can be done by your receiver--avoiding the need for a dedicated sound card if you have a receiver that supports these codecs.
But in my case, I don't have a receiver.