Make a videoconference call in skype

You can make internet calls for free with Skype. To sign up a Skype account:
http://www.skype.com/intl/en-us/home

For two people, it is straightforward, you can share video and audio by add  a contact and click call.

To make a video-conference call in Skype for more than two people:

1. First you need to create a new group,
click Contacts > Create New Group
2. Add people to the group
3. call group

For free Skype account, you can only have audio for more than 2 people.
You need to upgrade account to premium for video sharing for more than 2 people.