Books

Relationships, Dating and Marriage

Radical Friendship: Seven Ways to Love Yourself and Find Your People in an Unjust World by Kate Johnson

The Ethical Slut: A Guide to Infinite Sexual Possibilities by Dossie Easton and Catherine A. Liszt

Eight Dates by Gottman 

Come As You Are by Emily Nagoski

Attached: The New Science of Adult Attachment and How It Can Help You Find--And Keep-- Love by Amir Levine and Rachel Heller

The Seven Principles for Making Marriage Work: A Practical Guide from the Country's Foremost Relationship Expert by John Gottman, PhD.

Passionate Marriage: Keeping Love and Intimacy Alive in Committed Relationships by David Schnarch

Wired for Love by Stan Takin

Hold Me Tight by Dr. Sue Johnson

The Space Between: The Point of Connection by Harville & Helen Hendrix & LaKelly Hunt

The Set Boundaries Workbook: Practical Exercises for Understanding Your Needs and Setting Healthy Limits by Nedra Glover Tawwab

If you want books specifically about Ethical Non-monogamy (ENM or CNM) and/or Polyamory

The Ethical Slut, Third Edition: A Practical Guide to Polyamory, Open Relationships, and Other Freedoms in Sex and Love by Janet W. Hardy and Dossie Easton

More Than Two: A Practical Guide to Ethical Polyamory by Franklin Veaux, Eve Rickert, Tatiana Gill

Opening Up: A Guide to Creating and Sustaining Open Relationships by Tristan Taormino

A Happy Life in an Open Relationship: The Essential Guide to a Healthy and Fulfilling Nonmonogamous Love Life (Open Marriage and Polyamory Book, Couples Relationship Advice from Sex Therapist) by Susan Wenzel

Designer Relationships: A Guide to Happy Monogamy, Positive Polyamory, and Optimistic Open Relationships by Mark A. Michaels, Lyssa Browne, et al.

Polysecure: Attachment, Trauma and Consensual Nonmonogamy by Jessica Fern

When Someone You Love Is Polyamorous: Understanding Poly People and Relationships by Elisabeth Sheff

The Smart Girl's Guide to Polyamory: Everything You Need to Know About Open Relationships, Non-Monogamy, and Alternative Love by Dedeker Winston

The Lesbian Polyamory Reader: Open Relationships, Non-Monogamy, and Casual Sex 1st Edition by Marcia Munson and Judith Stelboum