And here's your Tolkien link for the day: Ardalambion: Of the Tongues of Arda, the invented world of J.R.R. Tolkien. This is a seriously hard-core site. And the author is actually updating pretty regularly (including yesterday).
Tolkien's languages were based on existing languages that he took his own way. Who could describe it better than the professor himself?
"The archaic language of lore is meant to be a kind of 'Elven-latin', and by transcribing it into a spelling closely resembling that of Latin...the similarity to Latin has been increased ocularly. Actually it might be said to be composed on a Latin basis with two other (main) ingredients that happen to give me 'phonaesthetic' pleasure: Finnish and Greek. It is however less consonantal than any of the three. This language is High-elven or in its own terms Quenya (Elvish)" (Letters:176).
Quenya was the ultimate experiment in euphony and phonaesthetics, and according to the taste of many, it was a glorious success. The grammatical structure, involving a large number of cases and other inflections, is clearly inspired by Latin and Finnish.