I read The Lord of the Rings at the urging of my mother, who said she read somewhere that it was a significant book in English Literature. I didn't read it exactly when she said it, because I wanted to read it in its original form. So in 2002, I decided that my English had progressed enough.
The story is very engaging and complex. The world has a lot of characters, with a lot of background. It's not a light read. The language is not easy. There are many thorough descriptions. Some I started to skip after a while.
The story is divided into three parts. The Fellowship of the Ring is about how the main character, a hobbit named Frodo gets together with a rag-tag group of humans, elves, dwarf, wizard and other hobbits. They have a task.
It was the best part. I loved the elven places in it, and the many adventures during the voyage. The team interacted very well together.
In the second part, The Two Towers, we see many places in the world as the characters travel. However, this was the most boring part for me. I found myself skimming this part the most.
The third part, The Return of the King, is when things escalate. This was a real page turner. Just when I thought it had all ended, there was more, and that turned out to be one of my favourite parts. It wasn't even in the movie.
I read The Silmarillion after this book. It provided valuable information for the story. I wrote a review for that book as well. It can be read before LotR, and that is perhaps better, but it may turn some people off Tolkien.
The movies are great, and provide a good visual, but the two things don't always match. It's better to read the book first, because the movies can be better understood that way.
Overall, this is a wonderful book, a real journey. It may require a level of maturity even for people whose first language is English. So if you pick it up, and feels too much at first, wait a few years and give it another shot.