What do I need to add to a basic PC in order to take lessons online?

[MisterTV]

I don't do any home recording and have never played a guitar through any kind of computer software.

My starting point is a relatively new (one year) HP desktop running Windows 7.

What are the basic purchases/downloads I would need to make if I wanted to pursue private instruction via Skype or a TrueFire sherpa?

 

[Promit]

Er... A webcam? I don't think people use audio interfaces for that stuff. Just have an amp at a similar to speaking volume and let the camera mic do its best.