J.R.R. Tolkien - General comments
Tolkien is the greatest of fantasy writers. Though he did not invent the genre, he did create the standard by which all others are judged.
Tolkien's primary works are The Hobbit, The Lord of the Rings Trilogy, and the Silmarillion.
The Hobbit was written as a fairy tale, and is geared more toward a younger audience. It is a necessary read for those interested in Tolkien, because the events in the story set the scene for the Lord of the Rings.
The Hobbit takes the reader on a journey with Bilbo Baggins, a pudgy Hobbit from a well-to-do land of The Shire on a quest that leads him through dragon lairs and troll haunts and Goblin mines. During the journey he happens upon a magic ring that is the center piece of the Lord of the Rings trilogy.
The Lord of the Rings follows the story of what happens after. It is the greatest fantasy work available, and is an absolute MUST for any reader.
The Silmarillion is almost a reference book, telling of the ages before the Hobbit and the Lord of the Rings in great detail, providing a depth and detail to this world that other authors can only hope of copying.
Tolkien is set apart from all other authors by his writing style. He was a professor of Middle English in England, and created the world of Middle Earth to appear as an Old English (pre-Norman conquest England) land heavy in myth and legend. His writing style, unlike many writers today, not only entertains, but is recognized as classic literature. What other author can claim to have created whole languages to enhance their worlds? The races and ideas of Tolkien serve to create the standard by which all otehr fantasy writers base their own creations. The modern ideas of Dwarves, Elves, Hobbits (or Halflings), Orcs, Goblins, Trolls, and more all originate from his works.
I recommend reading the Hobbit first (I know it seems a little juvenile, but you will need the background), then the Lord of the Rings. The Silmarillion is for those who like their settings to be full and three dimensional, it answers nearly every question the reader might have and gives the origins of nearly every name and character or reference in the LOR trilogy.