posted by shawn .
how do you describe an authors writing style and structure?
There are several sites in there that should help. (Skip the second link, though.)
Structure is however a writer decides to tell his story. Does he tell it absolutely chronologically? Does he use flashbacks at times? Does he tell a story within a story -- a frame story? (Poe's "The Oval Portrait" is such a story -- http://infomotions.com/etexts/literature/american/1800-1899/poe-oval-697.htm ) James Michener also wrote many of his novels in the form of frame stories -- Centennial, The Source, Texas, and many others.
John Steinbeck wrote his novel The Grapes of Wrath in a sort of checkerboard structure. Chapter 1 was background and philosophy; chapter 2 was the beginning of the story; chapter 3 was more background and philosophy; chapter 4 was the next chapter in the story; etc. Once I realized how he had structured the novel, it was much easier for me to understand where he was going with all this. Everything made more sense.
Writing style -- flowery, straightforward, spiraling, etc., etc. There are many, many ways to describe how writers write.