To enrol in Coursera courses in Audit/Participate with Listener mode for free, just follow these simple steps:
Create a Coursera account if you haven't already done sooner
Choose the course you want to take
Click Enrol
The enrolment page will offer you the option of "Audit the Course" or "Full Course, no Certificate". Click
or
Access the course materials: Once you have chosen to audit the course, you will have access to most, if not all, of the course materials. This usually includes video lessons, readings and discussions. However, remember that auditing a course does not give you access to graded assignments or a course completion certificate.
Start learning: With the course materials available, you can start learning at your own pace. Make sure you take notes and review the materials thoroughly to maximise your learning experience.