My boss has asked about setting up a "Webinar" or web conferencing so that he can present slideshows to our sales team spread throughout the country (the US). I think he'd like it to be a two-way communication, I'm not really sure though - what's our options with that?

Has anyone done this before? Any suggestions on how to approach this?

Thanks for any input.

PS - we're on Windows machines if that makes any difference