I would recommend the next two books in the Anita Blake series, The Lunatic Cafe and Bloody Bones.
These choices seem straightforward for the request, following the book reading order. I also think it would be worthwhile to confirm that the first two books in the series, Guilty Pleasures and The Laughing Corpse, had been read.
I would also recommend the Anita Blake: Vampire Hunter series of graphic novels that share the same titles as the books.
In suggesting the graphic novels I thought the patron may enjoy seeing the stories told through a visual medium. It is also an opportunity to broaden the patron's experience with an alternate form of reading, different than the traditional book.
2. What have I read recently? Well, I just finished this great book by Barbara Kingsolver, Prodigal Summer. I really liked the way it was written, you know, the way she used language. I wouldn't mind something a bit faster paced though.
I based this recommendation on the Novelist keywords from Prodigal Summer, "lush" and "lyrical." I also added the keyword, "fast-paced" and chose Johnson's book based on the "Romantic" tone listed in Novelists' Book Appeal Terms for Prodigal Summer, in connection with the short description of the book.
I would also recommend The Enchantress of Florence by Salmon Rushdie. For this recommendation I again used "fast-paced" and "lyrical" as keywords in Novelist, but replaced "lush" with "complex." This gave a different result list and I chose the Rushdie novel because he is a popular author and one I am familiar with.
I focused my searches on Novelist's "Writing Style" book appeal terms (those associated with Kingsolver's book), since the original question was concerned with the writer's style. Determining other keywords to use was trickier, not knowing what other factors may appeal to the patron.
3. I like reading books set in different countries. I just read one set in China, could you help me find one set in Japan? No, not modern - historical. I like it when the author describes it so much it feels like I was there!
My first recommendation, for fiction, is The Dragon Scroll by I. J. Parker
I made this choice based on the keywords, "Japan" and "historical" and "descriptive." This novel is the first in a long series and by suggesting it I thought that the patron would then have a clear continuation of books to read, assuming the initial recommendation was enjoyable.
My second recommendation, this time for non-fiction, is Kendo: Culture of the Sword by Alexander Bennett
I used similar search keywords for this recommendation, "Japan" and "historical." The keywords "richly detailed" offered more results than "descriptive." I also searched for just nonfiction titles. I chose this particular title because it offers a historical account of Japanese culture, something I think would assist the patron feel like he "was there!" It is also not entirely clear the patron is seeking solely fiction, so a nonfiction title is an appropriate choice, I think.
4. I read this great mystery by Elizabeth George called Well-Schooled in Murder and I loved it. Then my dentist said that if I liked mysteries I would probably like John Sandford, but boy was he creepy I couldn't finish it! Do you have any suggestions?
My initial recommendations are A Great Deliverance and Payment in Blood by Elizabeth George
Through Novelist I was able to determine that Well-Schooled in Murder is the third of a series. For this reason I suggested the first two novels in the Thomas Lynley series. This seems like an obvious first choice to me, given the available information.
I would also recommend Cover Her Face by P.D. James
For this suggestion I used the Read-alike option in Novelist. The keywords match nicely. I was also conscious of avoiding keywords associated with John Sandford that I thought could be construed as "creepy." These were "flawed," "violent," and "gritty." This is also the first book in a longer series, which may appeal to the patron, based on the fact that Well-Schooled in Murder is also part of a larger series. 5. My husband has really gotten into zombies lately. He’s already read The Walking Dead and World War Z, is there anything else you can recommend?
I would suggest The Rage, Volume 1: Zombie GenerationI found this title as a Read-alike to The Walking Dead, Vol. 1. I chose it because it was a graphic novel that featured zombies. It is collected in a series of volumes, much like The Walking Dead series. It appears to share similar similar themes of violence and action. The only matching keyword in Novelist with The Walking Dead series was "compelling."
I would also recommend The Zombie Autopsies: Secret Notebooks from the Apocalypse by Steven C. Schlozman
This title was a Novelist Read-alike suggestion for World War Z. I chose it because the synopsis/book description makes it seem similar to the same type of fiction as World War Z. A fictional story pretending to be nonfiction. I also made this suggestion because it is a novel, not a comic book, in order to balance the first recommendation, and to match the medium to the patron's initial comparisons. 
