Every Monday, the courses available for beta testing are listed in this resource
located in the Beta Tester Community course. This resource is updated around 4pm PT. Additionally, every Tuesday, the courses available for testing are also emailed to everyone in the Beta Tester community.
To start beta testing a course, click on the invitation link and accept the group invitation. Once you've accepted the policy, you can access all the course materials pre-launch and start testing!