We have lots of books here, including an extensive library of alternative health reads which was donated by alternative health expert and published author Jane Alexander.
Meanwhile, if you'd like to start before hand, you can research a little about the Cathars and the Albigensian Crusade in terms of history of the region. Lots can be found on the web, from the academic historical to the New Age hysterical. :-)
The yoga and philosophy books which continue to inspire Gertrud are:
Erich Schiffmann's Moving into Stillness. He has published other books also.
Christopher Wallis's books on non-dual shivanism and philosophy: Tantra Illuminated and Recognition Sutras
Mark Whitwell's Promise
I also enjoy these books, which explore the role of sexuality and women in Tibetan Tantric Buddhism:
Dr Nida Chenagtsang’s Karmamudra: The Yoga of Bliss
Miranda Shaw’s Passionate Enlightenment