The White Indians of Nivaria presents a simple overview of pre-contact Guanche culture, religion, and ancestry. It doesn’t go into much depth, and everything the author says seems to be true even with newer genetic research (although I couldn’t find more info about the blond pre-Columbian Andean mummies; if they exist hopefully someone does a DNA test). In the Q&A he criticizes esoteric Graham Hancock-esque theories about the Guanches as post-Atlanteans or refugees from a collapsed 10,000-year-old advanced civilization. On the other hand, he does believe that Guanches are descendants of explorers from ancient Egypt or a similar civilization, who brought their culture, religion, architecture, etc. to the Canaries and further west to America, seeding the civilizations of Meso and South America. This history (for the Guanches’ ancestors at least) seems close to true, as they had livestock and seaworthy boats.
Kennedy’s vision of the Guanches as the last white men living in Eden is romantic, but the book is not very evocative. The Q&A at the end is in some ways the most interesting part, and the whole book could have been a PDF.