I have taken the course once and it is rigorous with lectures, quizzes, and (important!) programming assignments that must be completed to advance. When you sign up, my advice is don't wait till the official start on July 11th; get started immediately. The exercises take real work but provide 90% of the actionable understanding.
Every Tuesday, bring your questions to the study group and we can learn from each other.
Conditions of attendance follow the Coursera guidelines:
1. All conversations must be respectful. There are no dumb questions or English-fluency barriers too high for this group.
2. I won't answer the quizzes or exercises for you. I'll explain the principles and try to correct your misunderstandings of the questions that are blocking you from getting to the answer yourself.
Instead of finally crossing off War and Peace this fall you can do something really amazing - learn Cryptography!