To get notified about new activities, courses and instructor opportunities, you must join the Google Group.
Click here to visit the group page.
Once there, you may need to sign in with your Google account. When you are signed in, you will see a button that says Join Group:
You will then see a dialog like this. You must choose "Send me an email for every new message". If you don't, you will not receive any notification emails, which defeats the purpose of joining the group to be notified.
If you have questions, please send an email.