I know Nothing about this. What would I need If I wanted to watch TV on my computer and also would I need a cable hookup or is there like a internet serice you suscribe to or something. Forgive my ignorance
Yes you will need a tuner / capture card like this PVR-250 or a video card with a video input. One advantage to the dedicated card is you wont be tied to the GPU software and are free to use 3rd party software like GBPVR.
If you have analog cable then just plug in and you are good to go, just plug into the card. With a set-top box (digi cable or sat) it is a bit more painful, you have to "capture" the output of the set-top to the card and is crappy quality and then you need to have the ability to change channels via a low-speed data port or IR-blaster.
The internet is really only needed for the guide / program info from guides like zap2it
You need a graphics card with video in. Or a video capture card if you want to record TV programs. Yes, you will need cable or satellite service. I know of no online providers that provides streaming subscription services. I do know that ABC, FOX, and maybe NBC are looking into providing subsription based online video content. Anything to get viewers to watch more commericals.
Unscramble channels are not a problem for a capture card or video card with video-in, but any channel that is scrambled will not unscrambled by either video cards. Scramble channels must be unscrambled by the cable/satellite box before being feed to the PC. Many video capture cards can also recieve unscrambled channels over the air (broadcast channels). Depending on where you are the signal could be good, or most likely bad with lots of "snow".