As another reviewer has pointed out, this is not a manual for writing erotica. This is about the place of sex scenes in mainstream fiction.
It is curious how the normal criteria for assessing the valdity of a scene, and whether it has a place in your novel, often go out the window when it comes to writing the 'sex scene'. This book discusses not only how to write such scenes, but how to assess whether they should be there at all - not on 'moral' grounds, but by the same criteria as all scenes should be judged: how do they advance the plot of the novel? What do they teach us about the protagonists?
And that is why this book is very different from one about writing pornography - it treats the sex scene as an integral part of the novel, not an erotic interlude.
Of course, this means that it does not restrict its remit to consensual, 'vanilla' sex. It also discusses the inclusion of sex scenes which deal with subjects that were previously taboo, such as incest and rape. This makes it a sometimes uncomfortable, but always informative read.