Long ago I tried to do one for Cloudlords, but all the diacritical marks made me crazy. ANy in particular giving you trouble?
I remember long ago in Pete's Middle-earth campaign, when the Silmarilion came out, we learned that 'Quenya' was really pronounced with the 'kw' as opposed to 'kenya.' And in the first Hobbit movie, you can hear Saruman say 'Istari' with the emphasis on that first syllable, not the second (IS-tari). Mind blown!