I’ve worked on and off as a freelance editor for years, guiding authors down the convoluted paths of writing both fiction and non-fiction for adults and children. I've also ghostwritten a few (nameless) books for a few (anonymous) "authors." In addition, for two years, I was the freelance editor for Alyson Books, during which time I worked on approximately 15 books of fiction and non-fiction.
Coming from a family packed with doctors, I have no problem with discussions of things gross and anatomical. And I'm not at all intimidated by the subject of sex.
My fee is $85 per hour, with a minimum of two hours, paid in advance. And just for the record, I'm a meticulous timekeeper, down to 15 minute increments.
I do substantial line editing (if necessary), make comments and suggestions on the page (from sparse to extensive, depending on need) and also write a separate detailed critique when the story calls for it.
The process depends on the demands of the story and whether the manuscript is a work in progress or if it's complete.
Note: I know from personal experience that pointing out a problem on without suggesting a way to fix it isn’t helpful. As a consequence, I offer practical solutions to complex problems to insure that you are not left holding a literary bag stuffed with discarded ideas.
Caveat Emptor: I tend to be straightforward in my comments. I don’t believe tiptoeing around issues is helpful when honesty is required.