It happens even in the best Book Club. Someone keeps showing up late, others do not read, someone is too shy, someone else takes over... Here is some advice for finding solutions for these moments.
There are some members who do not read for the sessions.
They might have a good reason for it so first investigate why they are not reading. It is very important to appreciate the fact that these members still come to the meetings. If it happens several times in a row, do ask them for explanations. If they do not enjoy the story, you can still keep them busy by asking them to prepare a presentation related to a topic raised by the book.
Some members always disagree with the others.
This can be made into an advantage and you can practise debate and communication skills. Prepare a list of functional language items for debates, and ask your Book Club members to use them during the discussions. Tell them that it is OK to disagree as long as they use appropriate language and can give reasons for why they disagree.
One of the Book Club members is too shy to join the discussions.
Be patient at the beginning, and just like with members who do not read for the sessions, appreciate the fact that they show up.
Try to understand why they are quiet during discussions. Do they feel intimidated for some reason? Are they shy to talk because of their pronunciation? Are they quiet by nature?
Find other ways of communication for your quiet Book Club members. Ask them to take notes during the sessions or prepare a presentation with images. This kind of guided and supported communication might help them overcome their fears. Try to involve them slowly. First just ask them if they agree or disagree with a statement.
Try a picture discussion session. You can find a post about the VTS method here. I’ve had very shy and quiet students who miraculously started talking during a picture discussion session.
One of the Book Club members dominates all the discussions.
Set rules at the first meeting, and revise these rules from time to time. If talking time becomes an issue, you can introduce talking time limitations. You can even use a timer, and give your students 2-3 minutes talking time. Take a small object like a hat or a ball that the Book Club members have to pass to each other during discussions.
One of the Book Club members always wants to use L1 in the group.
Setting rules might help here too. You can agree with your Book Club that if anyone has language difficulties, they can talk to you about it at the beginning of the meeting.