By "all the connectors on the back" I assume that you mean the video-in and out and TV and S-video, down on the lower right of the back of the machine. Those will be covered with Apple Video Player, which is either in with 9.1 or available from the Apple web site (I think 1.7.2 is the latest version).
Now, if you have an Avid card (you lucky bastard) in the PCI slot, it should also have A/V out jacks and stuff. It will be in the horizontal PCI slot near the middle of the machine, if you have one (unlikely). That software, for editing and exporting video, is going to be harder to find updates for, but you can try Apple's web site. I think it shipped with Avid Cinema, but I'd bet that iMovie is compatible with it. That's a great thing to have if it's installed.
Also, check out the specials page at MacresQ.com . They've got a remote control for your computer for $9.99 (brand new) which makes it just like a TV. It's the coolest thing. The MPEG card they're also closing out won't fit your machine, as it's a LC PDS card -- it goes in the 5200-6200 version machines and decodes (only) MPEG files in hardware. Yours is fast enough that Quicktime will decode MPEG just as well, with enough RAM.