Read any book you want to and meet up to talk about them, simple! Read as much or as little as you want it's really a conversation group so if you've not finished that 500 page biography it's all good.
Honorable mentions from the previous meetup:
---Books---
Wild Wood - Melot and Ellis
Combating Cult Mind Control - Hassan
Madame Bovary - Flaubert
May Goc: Beautiful Country Immigrant One - Chow
Moral Economics - Roth
Stories from the Tenants Downstairs - Fofana
The Merlin Saga - Stewart
The Five Invitations - Ostaseski
Papyrus - Vallejo
---Film and TV---
The Last Kingdom (2015)