I think you can get an awful lot out of The Lord of the Rings and related works by considering them in light of the author's life.
J.R.R. Tolkien was a philologist and linguist by profession and by inclination. In his day job, he translated foundational texts like The Greene Knight, Beowulf, and the Biblical book of Job. Like many academics in that field, he succumbed to the temptation to develop some constructed languages as a way of exploring his theories of language.
Central to Tolkien's linguistic ideas was, as I understand it, that language does not exist in a vacuum. Note that I'm paraphrasing very liberally here. A language is far more than just a grammar and a vocabulary used to exchange information, but rather is the medium of culture. A language cannot be adequately understood separately from the (written and oral) literature that conveys a culture among the language's speakers. A people understands who they are by telling stories in their own words, and all - the people, the stories, the identity, and the words - are necessary to really understand the language.
How can a person believe that and then still attempt to construct an artificial language? By constructing all of those necessary parts. He didn't just invent a grammar and a vocabulary. He invented legends, invented the people who understood themselves through those legends, invented the history of that people that provided the backdrop for those legends. And it wasn't just one language, but a whole slew of them, all originating in an invented world populated by multiple peoples. These processes of mythopoeia and glossopoeia were intertwined, and he continued them throughout his life, keeping the overwhelming majority of it private.
So the first, most important element of the Middle-Earth legendarium is that it is all about the language. When reading his work, you should revel in the prose and drink in the poetry. It's meant to be read aloud; The Hobbit began as a bedtime story he would narrate to his children. It's not merely that the rhythms of spoken English are part of the text, but that the rhythms of the text are part of spoken English.
In The Lord of the Rings, Tolkien positions himself as the localizer into English of a tome, "The Red Book of Westmarch," which had been diegetically assembled by some anonymous denizen of Middle-Earth, who had themselves produced it by compiling and transcribing a number of texts, the bulk of which were attributed to the characters Bilbo, Frodo, and Sam. This was a popular conceit in 19th- and early 20th-century fantasy literature, but it also reflects how absolutely crucial he considered it that the authorship of a text be placed in some historical context. Who wrote this book? What language did they write it in? What world was conveyed to that person through that language?
In order to create a fantasy with richness and depth, according to his own theories, the story had to be placed in a context. Bilbo, Frodo, and Sam wrote the book, but what legends native to the language that they wrote the book in helped them understand their place in their world? One of the most memorable qualities of The Lord of the Rings is best described by the professor himself: "Part of the attraction of the L.R. is, I think, due to the glimpses of a large history in the background: an attraction like that of viewing far off an unvisited island, or seeing the towers of a distant city gleaming in a sunlit mist." And the great wonder is that all of that large history actually existed, in the form of a copious assemblage of half-finished manuscripts.
The Silmarillion is a massive summary of the timeline of the world in which The Lord of the Rings takes place, including summaries of the three or four tales that were formative to the auctorial voice of the Red Book. This book is full of fascinating stories, but it isn't much of a novel by itself. If you're looking for a novel, in recent years, fully elaborated versions of them were assembled from various drafts: The Children of Húrin, The Fall of Gondolin, and Beren and Lúthien. They're all great, though they are as much works of historiography as fantasy fiction. Christopher Tolkien, in his capacity as "literary executor," painstakingly reconciled multiple incomplete drafts of each story, and devotes extensive parts of these books to a description of his decisions, if that's what you're into.
The other thing that's important to understand about Tolkien is his experiences in war, and the other other thing that's important is that he was incredibly Catholic. But that's a post for another day.