With the newest workings of Google Talk, the access is greatly simplified.
Here are the instructions:
Participants will need to have a Google account/G-mail address. Once you have established this, please e-mail Irene so that she can add your name to her list. At the time of the chat, please make sure you are logged on and your name will show on the chat list.
Then wait for Irene please to add you to the Group Talk.
Irene will be happy to have a trial chat with you.
Should you get "bumped," as occasionally happens, log off and on again, and Irene will get you back into the chat.