The information content is pretty standard for this type of book, but the delivery is a bit different. Written by an adult film actor (with help from an acknowledged ghost writer), the tone and style are more earthy than is usual for a sex guide. In other words, he uses the words regular people use, not the words doctors and therapists use.
There are the usual chapters on anatomy and sexual health that are very dry and matter-of-fact and probably have a lot more of the ghost writer's input than some other chapters. Mr. Marcus covers love and relationships, but most of the book is about seduction, foreplay, and no-strings-attached sex rather than sex in the context of an intimate relationship. The style is uneven at best and the material, while grouped in chapters with common themes (such as positions, manual stimulation, oral, kinky, etc.), does wander a bit. There are line drawings to illustrate the text, although some are repeated and they don't always seem to relate directly to the material on the pages where they appear. The drawings, too, are more graphic than those you would find in a more upscale book.
Despite his stylistic flaws, Mr. Marcus does seem to know what he's writing about and seems somewhat sensitive to the emotional dimension of sex. There's nothing really new here, but it's presented in a down-to-earth way that may be more appealing than books that are more clinical in their approach.