Hi Jennifer,
I know I've already helped you attend the session, but I wanted to write an answer for anyone else who might have this question.
The webinar links are turned off until half an hour before the session; The BBB webinar will turn on at 3:00pm for the 3:30pm webinar for instance. And the host of the show will be in the room shortly after it opens. I always like to have a little bit of a chat before we begin :).
Thanks,
Scott