To see an example of a GREAT webinar that follows this format, watch Brendon Burchard's webinar here:
http://www.youtube.com/watch?feature=player_embedded&v=-wXqJsbQE7g#
NOTE: Please watch the two training videos BEFORE you watch Brendon's webinar and read the mindmap I made of it.
If you don't, you'll miss all kinds of stuff and your webinar won't be as good.