You can find an eBook edition of this title on Google Play.
From a review in BuddhaDharma magazine: The Heart of the Path is a lengthy teaching on guru yoga by a contemporary exemplar of the practice, Lama Thubten Zopa. A close disciple of Lama Thubten Yeshe for more than three decades, Lama Zopa has taught by word and example the importance and power of properly following a guru. The book is based on several decades of dharma talks organized by editor Ailsa Cameron into twenty-four chapters, beginning with the question of why one needs a teacher to progress along the path. The remaining chapters discuss in considerable detail how to cultivate and practice devotion, and generate the view of one’s own teacher as the Buddha. It concludes with several short guru yoga visualization practices. Throughout the book Lama Zopa offers personal reflections and stories to illustrate his message that guru yoga truly is the heart of the path to liberation.
From a review in Tricycle magazine: For those interested in stepping beyond the realm of ideas into the world of practice, the latest book from Tibetan master Lama Zopa Rinpoche is a helpful guide to one important aspect of the spiritual path. The Heart of the Path explains the importance of guru devotion and Zopa's view of the proper way to develop a student-teacher bond. Lama Zopa has had many teachers, but his unwavering devotion to Lama Thubten Yeshe shines through on every page. Drawing on this experience and the Buddha's teachings, Zopa effectively conveys the value of relationships based on Buddhist ideals.
From a review in Mandala magazine: Although guru devotion is a foundational concept within Tibetan Buddhist thought, for many it remains a bewildering and impenetrable topic. Fortunately for contemporary practitioners, Lama Zopa Rinpoche has spoken extensively on guru devotion, giving teachings and advice about what it really means to have devotion to one’s spiritual friend. Drawing from nearly fifty teachings, this treasure is the result of seven years of painstaking editing by Ven. Ailsa Cameron. Not only does it include teachings on the traditional sub-topics that fall under guru devotion found in Tsongkhapa’s lam-rim, but also a useful outline to guide your reading, several supplementary  prayers and teachings from other renowned Tibetan masters, and inspiring images of Lama Zopa, Lama Yeshe and other amazing teachers peppered throughout. A perusal of this masterful work by Lama Zopa Rinpoche will assuage any doubts about the utility or possibility of “seeing the guru as Buddha.”
This book is made possible by kind supporters of the Archive who, like you, appreciate how we make these teachings available in so many ways, including in our website for instant reading, listening or downloading, and as printed and electronic books. 
Our website offers immediate access to thousands of pages of teachings and hundreds of audio recordings by some of the greatest lamas of our time. Our photo gallery and our ever-popular books are also freely accessible there. 
Please help us increase our efforts to spread the Dharma for the happiness and benefit of all beings. You can find out more about becoming a supporter of the Archive and see all we have to offer by visiting our website.
Thank you so much, and please enjoy this book.