Here's a link to Frequently Asked Questions about the Virtual Conference. #17 and #18 provide instructions on how to connect to the conference ...
17 - Where do I go to join the conference on September 30th? [Direct link]
and enter your login name and password. This is found on the lower left side of the page, and will not be "open" until 10:00 GMT on September 30th.
18 - What do I do if I have forgotten my password or login name? [Direct link]
Reminder emails will be automatically sent 1 week, a few days prior, and the day of the event with your login details and password. You may also visit http://www.proz.com/virtualconference
and click on the left side link that says "forgot password". The form will ask you to enter your email, and your password and login information will be sent to that email address.
[Edited at 2010-09-29 23:35 GMT]