The Genre Guide

Genre (literature) is a category of literary composition characterized by a particular style, form, or content.

Genre may fall under these two categories:

Fiction 

is something invented by the imagination of an author

Nonfiction 

is an account or representation of a subject which is presented as a fact. This presentation may be accurate or not; it can give either a true or a false account of the subject in question.
   e.g. The Diary of a Young Girl, Eat, Pray, Love, Bossy Pants

Here are some common genres in fiction:

Action

characterized by more emphasis on exciting action sequences rather than on character development or story-telling. Here, the protagonist usually takes a risky turn, which leads to desperate situations.
   e.g. Hunger Games, Da Vinci Code, Percy Jackson

Adventure

the protagonist journeys to epic or distant places to accomplish something. Usually this genre is mixed with others, especially action.
   e.g. Treasure Island, Lord of the Rings, Chronicles of Narnia

Christian

inspirational books which feature Christian characters and overt themes dealing with faith
   e.g Redeeming Love, Left Behind, Mark of the Lion

Classics

books which stands the test of time. This work merits lasting recognition and has a universal appeal.
   e.g. Pride and Prejudice, To Kill A Mocking Bird, The Great Gatsby

Comedy & Humor

a story in which the writer seeks to amuse the reader, sometimes with craftiness and as part of a carefully woven narrative, sometimes above all other considerations. This aims primarily to provoke laughter, but this isn't always obvious as it first may seem.
   e.g. The Hitchhiker's Guide To The Galaxy, The Princess Bride, Naked

Contemporary

its setting is generally after World War II.
   e.g. The Fault in Our Stars, Anna and the French Kiss, The Perks of Being a Wallflower

Cultural

refers to books that depict a place or time and its culture.
   e.g. Memoirs of a Geisha, Life of Pi, Henry's Freedom Box

Crime & Mystery

Crime genre includes the broad selection of books on criminals, courts, and investigation. Mystery genre is a loosely-defined term that is often used as a synonym of detective fiction - where a professional or amateur detective solves a crime.
   e.g. Sherlock Holmes, The God Father, The Girl with the Dragon Tattoo

Drama

the specific mode of fiction represented in performance.
   e.g. Romeo and Juliet, The Importance of Being Earnest, The Crucible

Epic

centered on heroic characters, and the action takes place on a grand scale.
   e.g. The Odyssey, Beowulf, The Hobbit

Family

focuses on the relationships of the members of the family.
   e.g. Little Women, My Sister's Keeper, The Lovely Bones

Fantasy

uses magic or other supernatural forces as a primary element of plot, theme and/or setting.
   e.g. Harry Potter, Game of Thrones, Eragon

Folk Tales

a general term for different varieties of traditional nature
   e.g. Grimm's Fairy Tales

Gothic

a genre that combines elements of both mysterious and romance.
   e.g. Phantom of the Opera, Frankenstein, Jane Eyre

Historical

presents a story set in the past, often during a significant time period. The time period is an important part of the of the setting and often of the story itself.
   e.g. The Book Thief, Outlander, Gone with the Wind

Horror

intended to scare, unsettle, or terrify the audience.
   e.g. The Shining, Dracula, World War Z

Romance

comprises two basic elements: a central love story and an emotionally-satisfying and optimistic ending.
   e.g. The Notebook, Wuthering Heights, Sense and Sensibility 

Sci-Fi

a broad genre of fiction that often involves speculations based on current or future science or technology.

   e.g. Ender's Game, I, Robot, Dune

Suspense & Thriller

Suspense is a feeling of uncertainty and anxiety about the outcome of certain actions, most often referring to an audience's perceptions in a dramatic work. A Thriller is characterized by fast pacing, frequent action, and resourceful heroes who must thwart the plans of more-powerful and better-equipped villains.
   e.g. Gone Girl, Deception Point, The Firm

Western

devoted to telling stories set primarily in the latter half of the 19th century in the American Old West, but there are also in contemporary settings. This often stress the harshness of the wilderness and frequently set the action in arid, desolate landscape.
   e.g. The Gunslinger, Lonesome Dove, Sackett's Land

Genres according to Age and Gender/Sexuality:

Children's

usually for readers and listeners up to age 12. It is often illustrated.
   e.g. Charlotte's Web, The Giving Tree, Charlie and the Chocolate Factory

Young Adult

written for, published for, or marketed to adolescents and young adults, roughly ages 13 to 21.
   e.g. Twilight, Divergent, City of Bones

New Adult

typically features protagonists between the ages 18 and 26. This tends to focus on issues such as leaving home, developing sexuality, and negotiating education and career choices. 

   e.g. Slammed, The Edge of Never, Beautiful Disaster

Adult

fiction intended for adults
   e.g. The Help, The Time Traveler's Wife, Water for Elephants

Women's

an umbrella term for books that are marketed to female readers, and includes many mainstream novels, romantic fiction, 'chick-lit,' and other sub genres.
   e.g. Bridget Jones's Diary, Devil Wears Prada, P.S. I Love You

GLBT

books for and/or focusing gays, lesbians, bisexuals, and transgender.
   e.g. Will Grayson, Will Grayson, Tipping the Velvet, Luna