WDW MM share

Can someone please explain in detail how to do one of these MM shares? We have a lot of newbies in the Jan 2017 FB page and we need help. One of the questions is do we all have to go the same week? TIA😘

What are MM shares?

Sharing Disney's Memory Maker: A step-by-step guide to sharing with family and friends this book was the best $1 I spent for MM sharing.