What is a summary of A Christmas Carol by Charles Dickens?

Charles Dickens' book A Christmas Carol is about a man named Ebenezer Scrooge, who is very selfish and mean. Early in the book, two men come to see him to ask for a donation to help the poor, and Scrooge refuses. He asks if all the jailhouses and poorhouses are full because that is where he believes the poor belong. His nephew also visits him to invite Scrooge to a Christmas celebration, but Scrooge tells him no as well. Bob Cratchit, a young man with a large family, works for Scrooge, and Scrooge is so tight with money that Bob is forced to work in a room with virtually no heat. His wages are very low, and he is expected to work on Christmas Eve. One of Cratchit's children is Tiny Tim, a little crippled boy.

The book is divided into parts called "Staves." In each one, a spirit visits Scrooge. First, is his deceased former partner, Jacob Marley, who tells Scrooge he will receive three visitors in the next three nights, and that he (Jacob), because of his greed, is suffering horribly in the afterlife. Scrooge still has a chance to redeem himself, but first he will have to meet the Ghost of Christmas Past, the Ghost of Christmas Present, and the Ghost of Christmas Yet to Come.

Each Ghost takes Scrooge on a journey. With the Ghost of Christmas Past he visits his childhood and young adulthood when he apprenticed for a happy go-lucky man named Fezziwig, and when he was engaged to the lovely Belle, who left him when she realized Scrooge was obsessed with money. 

Next, the Ghost of Christmas Present takes him to Bob Cratchit's home where he sees the family prepare for a tiny Christmas "feast," and even though they have so little, there is happiness. He especially notices Tiny Tim, who is both kind and brave.

Finally, the Ghost of Christmas Yet to Come shows Scrooge his own death, though he does not know he is the one who is dead until the end. Scrooge sees people talking about this horrible man with contempt and relief that he is gone. He pleads with the Ghost to tell him who this man is and is taken to a cemetery where he sees his own name on the gravestone. 

Scrooge promises to change, and when he wakes up the next morning, he is definitely a changed man. He celebrates Christmas by helping others, especially the Cratchits and becomes like a favorite uncle to Tiny Tim.