Here is a list of all related documentation pages:

Introduction
References
SHM Specification
Tutorials (C++)
Introduction to SHM
Tutorials (Python)
How to use high-functionaly server/client model (Action communication)
How to use Publisher/Subscriber model (Pub/Sub communication)
How to use Publisher/Subscriber model (Pub/Sub communication)(Python)
How to use simple server/client model (Service communication)
shm_pub/sub(shared memory publish/subscribe)