On a semi-related note, I would only recommend reading The Silmarillion and the Book of Last Tales if you are a die-hard LotR fan who wants to know as much about the history of Middle-Earth as possible. I've tried repeatedly to get through them, but have always ended up putting them away in disinterest.
The Silmarillion and The Book of Lost Tales can be terribly dry reading. In fact, at many times they read like a college textbook rather than an actual novel.
Some people really like them, but for me and a few of my friends, they are terribly boring.