I'm not sure what you mean by "internet tv."
I'm going to assume that you mean tv stations broadcast over the internet.
In this case, you don't need anything, besides your PC and your browser. Maybe some cables to connect your PC to your TV, if you want.
However, the problem is there's not too much content out there for this, at least for free.
You can try this site:
http://wwitv.com/
You can watch television channels from all over the world, but usually, it's boring stuff like C-SPAN for the States, and CPAC for Canada. Yay, watch Parliament in action *yawn*. Great for insomnia.