I was recently asked about Circus Fiction, so I thought I'd give a couple of recommendations. These should get you started.
Amanda Davis's Wonder When You'll Miss Me
Amazon Link
Amanda toured with the Bindlestiff's when I toured with them (in 1998)
She wrote this novel (her first, and sadly her last) after that. It's about a young troubled girl who runs away to join the circus.
Amanda was killed in a tragic plane crash along with her parents on the way to a book signing in North Carolina in 2003.
She was an up and coming young writer, and showed amazing promise. It's a real tragedy.
Katherine Dunn's Geek Love
Amazon Link
Great and classic book about a touring sideshow of self-made freaks and the religion/cult that develops about one of the performers. This is a book that consistently gets very high praise, and is consistently on the list of "Best Books About the Sideshow." HIGHLY RECOMMENDED.
Angela Carter's Nights At the Circus
Amazon Link
A book about turn of the century London turns into an epic love story between a cockney trapeze artist who may or may not have wings and the hotshot journalist that is set to debunk her as they tour the frozen steppes of Siberia. I was in a recent stage production of this, and the story and novel twist of this is astonishing and beautiful. It's a slightly long read and very narrative, but oh so worth it.
Search out More Books on Amazon that are circus fiction
Search out books on Amazon that are about clowns