The Fellowship of the Ring
This book begins the story and introduces Frodo and the One Ring. It also shows the beginning formation of the Fellowship of the Ring (hence the title.) It shows Frodo's journeys with Samwise Gamgee, Pippin Took and Merry, all hobbits, from the Shire to Rivendell while pursued by the mysterious otherworldly Black Riders.
This book shows how Frodo must go to Mount Doom and destroy the evil ring of Sauron. He and the rest of the fellowship  travel through the Mines of Moria , the glades of Lothlórien, and the rivers of Anduin. The book ends with the sudden breaking of the Fellowship due to Boromir's attempt to take the ring. Frodo and Sam go alone to Mordor down the river. 
Notes and references
- Frodo, Gandalf, Sam, Merry, Pippin, Aragorn, Boromir, Legolas and Gimli.
- Gandalf falls with the Balrog here.
- The Fellowship of the Ring, by J.R.R. Tolkien, Houghton Mifflin Company, 1954.