I have Dish Network going to my TV in my living room where my wife watches so I would like to have it going to my PC because we only have one TV. How can I do this?
That's the expensive way or, for the Sling Adapter which is free after rebarte, presupposes the OP has a 722/k. The usual answer is "coax" to a PC tuner card that still does NTSC capture.
Hauppauge HD-PVR or Elgato EyeTV HD are two other options. They can connect via Component (with the Hauppauge supporting pass-through as well) so you get a HD picture on your PC.
To watch live programming online you need a sling capable receiver. However, there are many shows and movies you can watch online with Dishonline, HBOgo.com, maxgo.com and from most websites of any channel. For sports I use myp2p and can see live games in my market and in most other markets. I get pro and college games.