The meeting
Even though you have been preparing for it for weeks, the book club meeting should be mostly hands-off for the person leading the book club. Trust that students and other staff will step up and bring their enthusiasm to the discussion, with minimal guidance on your part.
Letting students lead
Unlike a traditional English class, book clubs are about what the community gets out of a book, not what one teacher expects them to get. The most important discussion questions and topics are the ones that students bring into the room, followed by the ones that other staff participants bring. If these topics are so engaging that you never make it to your prepared questions, you have had an extremely successful book club.
Keeping things moving
Not all book clubs groups find their rhythm right away (and some never find it). Book club meetings require subtle leadership to establish and maintain momentum. Much of this can be accomplished during the introductory game. If the group starts diving into a deeper discussion about the book during the game, give them a few minutes to go there, then tell them you're making a note about what they're talking about and will bring it up again after the game is over (and follow through!)
Some discussion questions will be extremely engaging for the group. Others will flop completely. Both are ok. Don't fall into the trap of trying to give each question equal weight and time. If the group is engrossed in conversation, let them keep going. If there is silence after someone offers a one word answer, move on to the next questions.
Frame your leadership as questions and as an equal partner in the conversation. Rather than, “ok, let’s move on to the next question” try, “I was wondering, what do you all think about this?” This way, you, as the book club leader, will feel like an equal participant rather than the focus of the attention.