The Elfstones of Shannara, by Terry Brooks
It's the story of a quest to save a tree. A special tree. One protected by The Chosen. Too bad they were all gone. When the tree dies, defenses fail and the elf world might end. There's a slim chance it can be saved, and guess what? It is. Hooray!
If you like elves and deep, dense fantasy, you will probably like this book and the other Shannara books he's written. This PAL prefers his version of Star Trek Episode 1.