Introduction to Bhagavad-gita is a valuable companion to any edition of the Bhagavad-gita; Srila Prabhupada wrote it in 1968 as his introduction to Bhagavad-gita As It Is—before he even knew if he’d be able to publish the entire Gita—and included within it the essence of all the Gita’s teachings.
He begins the Introduction by advocating “submissive aural reception” as the proper mood for being able to understand the Bhagavad-gita at all. If we think the Gita is just another book, he says, we’re missing the point; its speaker, Krishna, is the Supreme Person Himself, and those who accept Him as such can get incalculable benefit from hearing His words. Introduction to Bhagavad-gita concisely explains all the Gita’s major themes, such as the difference between the self and the material body, how to prepare to leave the body at death, how our eternal dharma/nature/duty differs from what’s known as “religion,” the distinction between God and ourselves, how the personal feature of the Supreme is superior to the impersonal conception of God, and much more. This is one book introduction that’s every bit as useful as the book it was intended to introduce.