Main genre: Mystery, Crime, Thriller, Romance, Travel
Main audience: Young adult on
Main books: She's written over 80 books of fiction and also has written plays and travel/autobiography books. I don't know that there are any which are considered 'main books' because everyone seems to have their own favorites. My own favorites include The Man in the Brown Suit, Murder on the Orient Express, the stories of Tommy and Tuppence and Come, Tell Me How You Live.
Short summary of the author: Agatha Christie is the author of many mysteries, plays, short stories, romance and has also written suspense/drama as well as books of travel and autobiography. She's written under pseudonym Mary Westmacott and has been published with the name Agatha Christie Mallowan. (See below for more about the author.)
Points: Agatha Christie and her stories seem timeless. Even if the setting appears to be in a particular time period, and there is mention to telegraphs or items in the household which clearly date the story, it doesn't seem to matter. She has a distinct clarity and honesty in her writing, which is particularly clean and refreshing. She also looks at the world through eyes which see 'what is' and doesn't attempt to sugarcoat 'what is' but just accepts it is as it is (which isn't to say she condones it or agrees with it, just that there is no resistance in her to what she sees, which is a great strength).
This is some of what Goodreads has to say about Agatha Christie:
Agatha Christie is the best-selling author of all time. She wrote eighty crime novels and story collections, fourteen plays, and several other books. Her books have sold roughly four billion copies and have been translated into 45 languages. She is the creator of the two most enduring figures in crime literature-Hercule Poirot and Miss Jane Marple-and author of The Mousetrap, the longest-running play in the history of modern theatre.
Agatha Mary Clarissa Miller was born in Torquay, Devon, England, U.K., as the youngest of three. The Millers had two other children: Margaret Frary Miller (1879–1950), called Madge, who was eleven years Agatha's senior, and Louis Montant Miller (1880–1929), called Monty, ten years older than Agatha.
During the First World War, she worked at a hospital as a nurse; later working at a hospital pharmacy, a job that influenced her work, as many of the murders in her books are carried out with poison.