'Healing with Form, Energy, and Light: The Five Elements in Tibetan Shamanism, Tantra, and Dzogchen', by Tenzin W. Rinpoche
An excellent basic introduction to these subjects.
However, if anyone should choose to delve deeper into Dzogchen, or any of these practices, they would need to go find themselves qualified and experienced teachers to work with, which is why the text doesn't go into more depth.
When you're a novice and just starting out working with these kinds of energies, or even if you've been practicing for awhile, to really understand these things in depth and be safe, you'd really need to train with a qualified teacher, in addition to getting the transmissions directly and in person.
Just as in Kundalini Yogic practices, if someone just starts playing around with energies they don't understand, things can go "off the rails" and real harm can occur (physically and mentally).
So please do yourself a solid and if these teachings are of serious interest to you, do some research into which qualified teachers either live in your area, or are accessible to you; you might have to wait for a traveling teacher or go to another location.
It's worth it!
This is a book I've had for awhile and keep handy to re-read.
(I've been lucky & Blessed to have had some really excellent teachers; I love knowing that learning and experience are forever ongoing...)
Two thumbs up! 👍👍