Full of "action", "laffs" and "thrills", Pilkey's Captain Underpants series charts the elementary school careers of comic fans Harold and George as they battle against their child-hating principal, Mr Krupp.
Reasons for challenges: Offensive language, unsuited for age group Photograph: PR
The chronicle of a Native American boy who leaves the troubled school on the reservation and finds that he is the only kid at the high school in town who isn't white.
Reasons: Offensive language, racism, sexually explicit, unsuited for age group Photograph: PR
Asher explores the stresses and strains of high-school life with the story of a suicide in Middle America.
Reasons: Drugs/alcohol/smoking, sexually explicit, suicide, unsuited for age group Photograph: PR
This bestselling 'spankbuster' tells how high-flying sadomasochist Christian Grey seduces college student Anastasia Steele. Its commercial success has unleashed a tide of copycat erotica all around the world.
Reasons: Offensive language, sexually explicit Photograph: PR
The story of two male penguins who bring up a chick, And Tango Makes Three was inspired by a couple of male penguins in New York Zoo who hatched and cared for a chick.
Reasons: Homosexuality, unsuited for age group Photograph: PR
Hosseini's first novel tells how Amir is brought up alongside Hassan, at first befriending and then betraying him. It has sold more than 20m copies around the world.
Reasons: Homosexuality, offensive language, religious viewpoint, sexually explicit Photograph: PR
Miles Halter arrives at a boarding school in Alabama, where everything is rosy with new friends Alaska and Chip - until tragedy strikes.
Reasons: Offensive language, sexually explicit, unsuited for age group Photograph: PR
Schwartz's first volume of spooky folklore and grisly urban legend, complete with haunting illustrations by Stephen Gemmell, was first published in 1981.
Reasons: Unsuited for age group, violence Photograph: PR
This memoir charts a difficult childhood, with a mother who called herself an 'excitement addict' and a father who descended into alcoholism.
Reasons: Offensive language, sexually explicit Photograph: PR
First published in 1987, Beloved tells the story of Sethe, who kills her eldest daughter rather than have her taken back into slavery in Kentucky.
Reasons: Sexually explicit, religious viewpoint, violence Photograph: PR
