Skype accounts are free and screen sharing is a great way to get support and training when you both can't be in the same place.
You don't need to have a webcam to screen share - the other person is getting sent a version of the same information that is sent to your monitor. It can be a bit slower but it's worth it to be able to understand a problem fully.
Skype is at http://www.skype.com/en/
A quick video about screen sharing is at https://support.skype.com/
