Decide what you feel would be a comfortable mix for your discussion group. If you want to mix male and female members, the book choices and discussions will need to be on a wider range of topics so that no one feels like they are in the middle of an all sports or all romantic comedy novel discussion. The main thing is that the group be small enough so that everyone gets a chance to be heard and that you can be open enough to all agree on one book at a time.
Think about the other parents who are dropping their kids off to school. Do you get into conversations with one or two of them? Ask them about joining a book club. You might know enough about your neighbors to know if someone would be interested in joining. And there's always work friends and acquaintances.
If you can get eight people to commit to a time and six do arrive, that's a perfect small group that you can manage without feeling like you're throwing a cocktail party every week. And establish that everyone will share in bringing beverages or food to the discussion group meeting and that either you'll rotate houses or you'll always meet at one home. Get e-mail addresses for a quick reminder the day before each meeting.
Unless the group is specifically organized for it, don't begin with anything religious or graphic in language. Begin by asking for suggestions at your first meeting. There could already be a consensus on a first book based on something everyone wants to read. If not, concentrate on classic or current bestsellers since they'll be easy to find in a library or bookstore.
You can also start by author. Jane Austen, John Updike and popular mystery writers are always a good start. And once you choose one book, the group will be more aware of each other's tastes and preferences by book No. 2.
Start with themes. Literally ask the question, "What do you see as the theme of the book?" This gives an overview for a starting place. And within that discussion, character development and storyline thoughts will emerge. As group leader, keep track of those lines of communication and follow up to get everyone's point of view.
Remember, no one is right or wrong; everyone can read a book and find new and different things and nothing is invalid to discuss.