I’ve never been to a book reading group but I imagine they are geared primarily to people who have already read extensively and who are used to commenting on that experience, the attendees will either have had the book topic/title chosen for them or perhaps by collective agreement. The Reader Organisation is a charity whose aims are to attract people who may not, for a variety of reasons, like myself, had that opportunity, and for whom it might appear intimidating, people in care, psychiatric units,residential homes, prison or similar, the potential is exciting. http://thereader.org.uk/
They promote book reading groups with a difference, the participants may not have pre-prepared the reading before the meetings, the Reader consider that it is the shared reading aloud that is therapeutic, improving reading ability and confidence in expressing opinions about the novel, author, historical period, possibly relating it to their life experience.
Check out their site and current training courses, sometimes there are concessionary trainee facilitator places.
It would be good to see a group and training in Leeds, perhaps one exists, already, please comment on the Leeds Wellbeing blog if you are aware of it, participation in a similar group could be an aid in maintaining better health.
The Reader site indicates that they can deliver training for interested groups and gives relevant contact details.