These three books have helpful chapters on a number of topics related to sex in the context of marriage, but also speak to sex and the single Christian, especially the book by Richard Foster.
The first book, Sacred Marriage: What It God Designed Marriage to Make Us Holy More Than to Make Us Happy? by Gary Thomas has been the foundational text for this six week series. As I said a number of times during the series, Thomas writes in an engaging, easy-to-read style that is both thoughtful and practical, helping both men and women to see the relevance of God to our marriages.
There's a reason why lots of folks are reading this book - it's practical, biblical - bottom line, it speaks to where most people are struggling in marriage today, and gives insight and encouragement in building a lasting "holy" marriage that enriches our lives.
The second book, by Richard Foster, is The Challenge of the Disciplined Life, which originally had the much better title, Money, Sex and Power - because that's what this book deals with head-on: our culture's infatuation with money, sex and power. Foster examines each of these topics for several chapters, helping the reader understand God's perspective on each of these areas of life.
His chapters on sex are excellent, and he deals with "chastity" from the perspective of singles, but also from the perspective of the married person, who is also called to live in chastity and faithfulness with their spouse. Spiritually renewing and encouraging, this is a book that will deepen your faith and your understanding of the influence of money, sex and power on your life.
Finally, one of my Top Five books of all time for men, is Healing the Masculine Soul: How God Restores Men to Real Manhood, by Dr. Gordon Dalbey. This book was first published in 1988, and it was groundbreaking at that time (I think I found it around 1994 or so).
Like Foster's book, this book also went through a slight title change; it was originally published as Healing the Masculine Soul: An Affirming Message for Men and the Women Who Love Them. I mention the original title because I do think wives ought to read this book as well; it will help explain your husband, and if you have sons, it can help you both understand them, and launch them into manhood in healthy ways.
One of Dalbey's main concerns is that in our modern/western culture, we have no identifiable rite of passage when boys become men. This leads to prolonged adolescence and a sense of loss in many men. Add to this (or because of this there are) the fractured relationships between fathers and sons, and you have a culture of men who don't really know what it means to be "a real man," leading to all kinds of inappropriate and hurtful behavior for relationships between men and women.
All three of these books are in print, and they are usually in stock at Parables Christian Bookstore here in Omaha.