HOW MUCH PLOT DETAIL DO I NEED TO PROVIDE?
As much or as little as you wish.
Clearly, the scope of the project will depend upon what you have created as the vision for your novel.
You might already have a very detailed plan. For example, you can describe key scenes and plot developments. You know the setting of the novel and the various subplots, and you can describe your characters in detail. In this case, you certainly have a structure already set out in your mind, so we would be adding “flesh to the bones” of your story.
On the other hand, you may simply have a very vague idea for a book. For example, you may want us to create a novel to enthral your children, about a Victorian inventor, who uses his remarkable scientific knowledge to build amazing contraptions to solve crimes in gas-lit London – but that’s really all you have. In this case, your My Ghost Writer™ novelist would be taking your basic concept, and creating plot lines and characters – in effect “building the bones as well as the flesh to go on them” ... but that is, of course, absolutely fine too.