What programs can I use if I want to communicate through video conferencing?

There are many options available for you including, but not limited to, Elluminate, Skype, Lync, and Live Meeting.

Elluminate: Elluminate Live! was a web conferencing program developed by Elluminate Inc. Elluminate “rented out” virtual rooms or vSpaces where virtual schools and businesses can hold classes and meetings. Elluminate has been acquired by Blackboard Inc. While Elluminate is primarily designed and used for educational purposes, it is also used by training organizations and corporations. K12 Inc., Desire2learn and several other schools and businesses use Elluminate live as part of their curriculum and meetings.
For more information on Elluminate, refer to: http://www.elluminate.com/Services/Training/Elluminate_Live!/?id=418

Skype: Skype is a proprietary Voice over IP service and software application. The service allows users to communicate with peers by voice using a microphone, video by using a webcam, and instant messaging over the Internet. Phone calls may be placed to recipients on the traditional telephone networks. Calls to other users within the Skype service are free of charge, while calls to landline telephones and mobile phones are charged via a debit-based user account system. Skype has also become popular for its additional features, including file transfer, and videoconferencing. Competitors include SIP and H.323-based services, such as Linphone and Google Voice.
For more information on Skype, refer to: http://beta.skype.com/en/

Lync: Microsoft Lync is an enterprise-ready unified communications platform. Lync connects people everywhere, on Windows 8 and other devices, as part of their everyday productivity experience. Lync provides a consistent, single client experience for presence, instant messaging, voice, video and a great meeting experience. Lync 2013 users can connect to anyone on Skype, enabling rich communication with hundreds of millions of people around the world
For more information on Lync, refer to: http://lync.microsoft.com/en-us/what-is-lync/Pages/what-is-lync.aspx

Live Meeting: Microsoft Office Live Meeting is a commercial subscription-based web conferencing service operated by Microsoft. Live Meeting includes software that is installed on client PCs, and uses a central server for all clients to connect to. Currently, those servers are under the control of Microsoft, however, Microsoft also produces Microsoft Lync Server , which is an enterprise conferencing server product.
For more information on Live Meeting, refer to: http://office.microsoft.com/en-us/live-meeting-help/demo-microsoft-office-live-meeting-HA010240323.aspx