This is a wonderful book, but it certainly is not for beginners and it's not for people who haven't had any exposure to Buddhism/eastern religion. I would also argue that an understanding of Kashmir Shaivism helps when reading this book--It's a philosophy that's closely related to Bön Buddhism but it rectifies the ontological mistake that Buddhists make when describing sunya (void). Sunya isn't "emptiness" or "void", even though it is sometimes translated that way. It is the pulsating, vibrating light (spanda) of the universal subjectivity that creates the universe and exists in all living beings. It comes from the fusion of purusha and prakrti, Shiva and Shakti. When experienced directly, this fusion turns into the transparent luminosity of awareness, much like the rigpa that is described in Bön Buddhism. It's simply a different way of describing and understanding the same phenomenon.

That being said, the visualizations and practices that this book presents in the context of Bön Buddhism are very helpful for people who are interested in dream yoga and yoganidra. I've seen some progress already in my dream state and I haven't even been practicing for very long, which tells me that the Tibetans are really onto something with this upaya. Would highly recommend for meditators who are interested in taking yoga to the next level!!