The Hobbit is a seminal book in my life. Although I read a little when I was very young, I fell out of the habbit, and sport, movies, tv etc took over.
When I was about fourteen a friend of mine lent me the Hobbit, and I took it away with me on a holiday. I became completely absorbed in the book, when I looked away over the fields at night I could imagine Tolkiens orcs creeping silently towards me through the grass. I ended up reading the Hobbit many times and it reignited my love of reading. From there I devoured everything I could find of Tolkiens, the Lord of the Rings, the Silmarillion, Unfinished Tales, Farmer Giles of Ham, Smith of Wotton Major, Leaf by Niggle, even some translated poems. From there I went onto other books, indeed I have never stopped reading.
Anyway back to the book, the crux of the book is Bilbo, indeed he is "The Hobbit". One of the things I liked about it as a child, that it is not a story about a child, but one could still empathise with the Hobbit, being about the same size as a child, somewhat sheltered from the world. He is taken far from the comfort of his home, through fantastical adventures and trials, all the while discovering reserves of courage and wisdom he never knew he had.
I think that is a great message for children, but I also think adults who don't take themselves too seriously might also enjoy this as a light read.
The book starts out in a very story-tellerish manner, but as it goes on the writing style matures, so I recommend if you start it, make the effort to finish it or you will have missed out on what it is about.
Finally, it is also the precursor to the Lord of the Rings, so to find out where the ring and Gollum came from you will just have to read it.