Post-Isengard

In the book, Gandalf talks to Saruman after Isengard is destroyed by the Ents. He asks Saruman to give him his staff and the keys to Orthanc before being allowed to leave Isengard and go wherever he wants to. Saruman denies the offer and Gandalf leaves the Ents to guard him in his tower.

The Palantír - 1

In the book : The Palantír is not found by Pippin, but thrown by Grima out of a window of Orthanc while Saruman is still talking to Gandalf and his companions.

Frodo & Sam

Frodo and Sam never get seperated in the book, because Frodo knows that he will never reach Mordor without his companion.

Gollum's End

In the book : The fight between Gollum and Frodo in the Crack of Doom does not end with them both falling down into the Orodruin. Like in the movie, Frodo and Gollum fight, but when Gollum manages to bite off Frodo's finger, with the Ring on it, he jumps around in joy and accidentaly falls on his own.

How did the Sword come to Aragorn's hands ?

In the book, it isn't Elrond who visits Aragorn in Dunharg, but his sons (Elladan and Elrohir) while there is no need for the Sword of Kings to be taken to him, because Aragorn had it right from the beginning of the journey of the Fellowship, having asked the Elves of Rivendell to reforge the blade before he left Rivendell. But the twin sons of Elrond take him instead words of advise and the right hint for him to take the path of the death.

Who's in the Path of the Death ?

While in the movie only, Aragorn, Legolas and Gimli enter the path of the death, the three companions, in the book, are joined by Elrond's sons and a group of Rangers from the North that had come to them at Dunharg.

The Palantír - 2

In the books, Aragorn uses the Palantír to show himself to Sauron. Another character who uses a palantír is Denethor, but that is not told in the movie.

Aragorn's Sword

To proove to the Army of the Death that he is the King of Gondor, Aragorn does not raise his sword like he does so in the movie. In the book, he raises the shield showing the sign of Gondor.

House of Healing ?

In the book, Théoden does not die in Eowyn's arms, but in Merry's. This difference is necessary, because in the movie the House of Healing are not mentioned. In the book, Eowyn is left unconscious by the breath of the Witch King and brought to the Houses of Healing where she and other wounded people are healed by the King.

When Faramir meets Eowyn

In the book : In the House of Healing, Eowyn and Faramir meet for the first time and fall in love with each other. Later they marry.

Frodo is living

In the book : When aragorn and his companions reach the Black Gate, intending on drowing the orcs away from the plains of gorgoth, Aragorn meets the mouth of Sauron. The herald of the Dark Lord shows him the mithril vest and Frodo's clothes, leading Aragorn in to believe that the Ringbearer was captured and killed.

What happens to Saruman ? - 1

In the book : At the end of the story, the Hobbits return to the Shire and are joined by their old companions. On their way north they meet Saruman and Grima, dressed as beggars, but they let them go.

Bagend

In the book : The Hobbits find out that Bagend has been taken by the Sackville Bagginses. They free Bagend and the whole Shire from the Orcs.

What happens to Saruman ? - 2

In the book : In the Shire, the Hobbits meet Grima and Saruman once again. While Grima cuts Saruman's throat, but he himself is slained by the Hobbits.