You dont need a web cam to take advantage of this service but it would be beneficial so that your technique can be checked visually to avoid getting into bad habits. It doesn't need to be a state of the art webcam, as long as you can be seen.
You do need a microphone so that you can be heard speaking and playing and a fairly modern computer that can cope with video chat and a reasonable broadband link. If you already successfully use a video chat or conferencing service then there should be no issues.
Our preferred method of delivery is Skype, but we are happy to try to accommodate any other free services you may already be comfortable with.
If you are thinking of buying a webcam, try to get one that is UVC or driverless. This makes life easier to get going.
Microphones on webcams are generally tailored to providing the best quality speech and may cause problems when playing a musical instrument through it. You may therefore need an inexpensive microphone to plug directly into the computer.
To test this, record a short video of yourself just strumming the guitar at a comfortable listening volume for you. Most webcams come with some sort of recording software. If the sound is clear with no distortion or crackling on the recording, the microphone should be fine.