The Children of Hurin is a piece of the history of Middle Earth from before the time of The Hobbit or The Lord of the Rings. It's a time when men and elves were fighting orcs, dragons, and the original dark lord Morgoth.
This book is much slower going than The Hobbit. It's like the Old Testament. There are pages of pretty boring stuff surrounding exciting little gems of story. Towards the end the book gets better, but it is a dreary tale of a cursed family. It's worth reading to get a better understanding of the back story for other works of Tolkien. However, it's not an exciting read and I've found myself putting it aside to read more interesting stuff for a couple of months now. Recommended with reservations.