For those of you who have not yet tried reading Tolkien's posthumously published works, you can find the twelve volumes of The History of Middle Earth in rather user-un-friendly - but free! - online versions at this website. A real treasure trove.
This provides access to The Notion Club Papers (Volume 9), The Lost Road (Volume 5), Athrabeth Finrod ah Andreth (Volume 10) and a lot of interesting stuff about elves and dwarves (Volume 12).
If you enjoy these, you will probably want to buy paper copies of all twelve books; but these versions provide a comprehensive taster.
