-
You're not a proper fan until you've read the 12-volume 'History of Middle-earth' and 'History of the Lord of the Rings' cover-to-cover.
More seriously, you might enjoy Christopher Tolkien's re-casting of the classic Silmarillion tales: The Children of Húrin, Beren and Luthien, and The Fall of Gondolin. (The latter is probably the weakest edition of the three, as the story really wasn't finished, but still worthwhile.)
Read LOTR way too many times as an unhappy youth. The Silmarillion too. Yes, that bad.
Currently my daughter is reading The Hobbit, she has to read out loud for 10 mins a night and am quite enjoying it.