The links for the books and the audiobook listed below will take you to Amazon. And you can find many more resources, including videos and downloadable guided meditations, at the three websites listed at the bottom.
Self-Compassion: The Proven Power of Being Kind to Yourself, by Kristin Neff
The Mindful Path to Self-Compassion, by Christopher Germer
Mindful Compassion, by Paul Gilbert and Choden