This may be a dumb question, but: do I need a good graphics card if I intend to get an Oculus Rift? Does OR plug into a GFX port, like HDMI?
You need one that renders your game at a minimum of 60fps at a minimum resolution of 1280x800 at whatever other settings you choose.
That's for Dev Kit 1!
For the next dev kit, who knows - it was running at 1920x1080 at 95fps when they demoed it.
For the consumer unit - again, who knows. They may up the resolution to 2560x1440 and the refresh may, or may not be 60 or 95.
It plugs into HDMI, but the DK1 did come with an HMDI -> DVI adaptor - it's basically just another monitor as far as your computer is concerned.