So I was interested in setting up broadcasts of live TV to stream to friends, but I don't really have any idea what I need to do it in terms of hardware/encoding software. Anyone able to give me some pointers to get started on it?

Edit: After looking around at some stuff I can get a bit more specific with what I need help with...I have a PC that should easily be capable of whatever it needs to do on its ends. I have Comcast Digital Cable(standard def), that comes in via coax cable. I have this guy currently in my machine for recording off of my game consoles. There's no output from my TV, and no coax input on the capture card, so I'd like to convert the QAM signal from the cable box to HDMI or some sort of component cable or S-vid or some shit so I don't have to buy a different card.

I'm not super familiar with coax stuff, ideally I'd want to split the cable signal so that I can watch the program normally on my TV while the other cable runs into my PC to stream it.