Author JRR Tolkien started writing about the magical world of Middle Earth in 1916, and didn't stop untill he died in 1973.
He didn't just create a set of stories, but a world with its own languages peoples, cultures and history. In many ways, it was never completed, but it was still a very impressive work.
The Lord of the Rings was just a small part of the whole story of Middle-earth, which took in The Hobbit, the Silmarillion and many other books. This guide tells almost all the story, so if you haven't read the Lord of the Rings, you may want to stop now.