I have real ideas to share about book clubs further down, but my first suggestion is: Write a book, have your daughter's book club read it, and then have a ridiculously good time talking to a bunch of bright, engaged, adorable readers.
If you're considering starting up a book club for your kids, I can recommend it. Lucky for me, a friend initiated ours. We often have a craft set up for the kids that's associated with the book. For Horus, the host provided several crafts--the kids made mummies from Popsicle sticks and white yarn and (I think) googly eyes. The children also decorated bookmarks with bat & mummy stickers, and they even had little wooden coffin "sarcophagi" to paint!
When the book club read a Magic Tree House book, we printed out blank comic strip pages so the girls could make their own comics about it or write different stories about the characters. They also enjoyed stringing their own bead necklaces.
After discussing a Beasts of Olympus book we went out to the driveway and the club drew an obstacle course with colored chalk. I can't even express how cool it was watching these children drawing details they remembered from the book--mythical beasts to dodge, the river Styx to jump, etc.
Here's a link to a few more ideas. Have fun!