Naturaly the book has got a lot more imformation that the movie, but the movie did destroy the story in a terrible way, they tried to make the movie shorter and try and make it good, but they left out several important and interesting parts from the book. They also appear to have put in extra bits of imformation.
From the beggining of the movie it is differnt, they have a background about the ring and Isildur taking the ring instead of destroying it, this was writen in chapter 2 of the book.
In the book Bilbo departs with three dwarves, this could have been easy to include into the movie without wasting to much time. And it seems strange that Bilbo could make it all the way to the Elves by himself.
The movie made Pippin and Merry out to be of a mischievious behaviour, but this is not so much present in the book, for instance they do not launch off the big dragon fire work in the book. After a while in the book you discover you discover something that the movie totaly overlooked, Merry was part of a conspiracy that watches people in the Shire, they new all about the ring and of frodo having it, Sam is their main spy. This explains the part where he was listning into the talk Gandalf and Bilbo where having when he got caught for evesdropping.
The part between where Bilbo leaves and Gandalf discovers that it is the ring of power is very short in the movie, but in the book it is over twenty years, Gandalf is trying to learn about the ring for all this time.