A theme should be set for the year, such as k-12 education in different cultures, technology in our western lives, civil discourse, childhood, or inclusivity in school cultures.
The first book should be a chosen by the faculty.
The second one should be chosen by the parents.
The third should be chosen by a student committee.
The most important part is the sharing of ideas at each meeting. Rules of discourse should be created at the beginning of the year by the group in attendance at the first meeting. I would expect a more bonded community to evolve, with increased respect, trust, and understanding for in both groups.