Tolkien created several languages which appear in Middle-Earth. The best defined of these are the Elvish languages of Quenya and Sindarin, which are based on Welsh. The tongues of men are based on Old English.
There is no such language since Elves don't really exist, but Tolkien in his books used runes as elvish. You can find books on runes and rune stones.
Tolkien created many fantasies. The first was The Hobbit. They all were centered around Middle Earth. Other books included The Lord of the Rings and the Silmarillian.
There have not been any published books that have used Tolkien's elven language. There are numerous 'fan' written stories that have used Elvish and some attempts have been made to write entirely in elvish, but none have been made available commercially.
Tolkien intended for his books to be read and enjoyed by the world. The Silmarillion and some of his other works, however, where never completed or published.
The author, Christopher Paolini, was inspired to write the Eragon series after a dream he had about a young dragon and his rider. He began working on the story at the age of 15 and self-published the first book when he was 19.
Royd Tolkien is the great-grandson of J.R.R. Tolkien, the author of "The Lord of the Rings" books. Royd Tolkien is known for his work as a film producer and his involvement in sharing his family's legacy and stories.
They are considered Fantasy.
J.R.R. Tolkien credited his mother, Mabel Tolkien, as a key influence in his love of books and learning. She introduced him to a wide range of literature and nurtured his imagination from a young age, setting the foundation for his future success as a writer.
Tolkien did not seek fame. He was a private person who preferred a quiet life with his family and close friends. His passion was storytelling and language creation, rather than seeking recognition or celebrity status.
The Silmarillion.
His books are usually considered fantasy.
Any posting of the books online are in violation of copyright laws and illegal.