Originally, I set up courses to become available as members level up. You level up here by posting and liking comments in the Community section. But there are not enough comments yet to really allow that kind of ranking system. So (at least for now) all non-premium courses are unlocked after being a member for a certain amount of days. After 28 days, all free courses will be open to members. I hope that you all are able to find something of value in the newly opened courses.
Also, once you complete a course, please make sure to check it off as complete. This helps me know when I might need to start writing more material. If it looks like no one is completing anything, I will be less motivated to write new courses.
And as always, post suggestions and criticisms here anytime. I appreciate honest feedback.