A book club is like a group of people getting paired weekly to read each other's books. Each book club has different rules. 

Some book clubs would pair you to only one partner and you're supposed to read three of their chapters and give an honest feed back and so are they. 

While other book clubs would make small groups. You get to have four partners so four people read your first chapters and so on.

Some other book clubs give you a month or so to read the entire book, giving you full feedback.

Book clubs' rules differ and each book club has it's own rules posted as in the first or second chapter in their book.You can check my profile where you will find this reading list that's called "Book clubs" you can read the rules and join whichever floats your boat.It helps you gain LOADS of reads and long helpful feedbacks.Feel free to ask me about any more details!