Not to be a total nag, but a lot of these questions can be answered by reading
The Silmarillion or
Unfinished Tales. Actually, I'd recommend them to anyone the least bit into
The Lord of the Rings.
The Silmarillion tells the complete story of the creation of Middle-Earth and the First Age, as well as including a history of Numenor and a brief overview of the Third Age.
Unfinished Tales contains some more in-depth sections of stories from all three Ages, including a longer version of the story of Turin and more details about Numenor. Of course, if you're feeling really adventurous you can get into
The Book of Lost Tales 1 and 2. These are collections of some of Tolkien's earliest writings on the history of Middle-Earth; it's interesting to see how they evolved into the content of
The Silmarillion. Of course, everything besides the actual trilogy and
The Hobbit was edited by Tolkien's son Christopher, since Tolkien never really created a fully finished version of
The Silmarillion. Over much of his life, he re-wrote many of the stories related to the history of Middle-Earth, and some reached a more polished version than others. One story that he never really finished was the tale of Tuor and the fall of Gondolin; a shorter version is in
The Silmarillion, and there's the start of a more in-depth tale in
Unfinished Tales, I think, but never the fully detailed story. Christopher has said that that's the one story he most regrets that his father never finished.
As you can tell, I'm a huge Tolkien fan
. There are some other books available beyond the ones I mentioned above, including some of the epic poems/songs that Tolkien wrote regarding Middle-Earth (such as the "Lay of Leithian," for instance), as well as a
History of Middle-Earth set that includes some earlier versions of elements of the actual
Lord of the Rings trilogy. I haven't really gotten into any of this later work yet, but I hope to in the future.
