A review by wandering_not_lost
The Joy of Writing Sex: A Guide for Fiction Writers by Elizabeth Benedict

informative

4.0

A good book for writers both about how to Deal With writing sex on a personal note (because of how many hangups can be involved) and in what factors to think about when plotting sex into your stories.  It's pretty dated now, as sex via email/forums/chatrooms seems to be about as advanced as the tech was when the book was written, but it's still got some good points about what sex means, how people/characters make decisions about sex, and how to describe sex in ways that isn't too much or too little.

Also I was interested in how similar the advice in this book was to the advice in a book about including fighting and violence in books:  it's a highly emotionally charged thing, it draws attention, but unless you want to seem gratuitous, it's got to mean something to the characters and the plot other than just doing the deed.