The most comprehensive set of videos of Dr. Porges talking about the Polyvagal theory can be found here on his website. These are updated regularly.
In addition to Dr. Porges’ books, we unhesitatingly recommend the work of Deb Dana, LCSW. Her Polyvagal Theory in Therapy is exceptional. You can access her publications here.
In addition, with her permission, please find her lucid and brief PDF ‘A Beginner’s Guide to the Polyvagal Theory below.
DOWNLOAD DEB DANA LCSW'S "BEGINNER'S GUIDE TO THE POLYVAGAL THEORY"