The Science Fiction Timeline Site is quite cool. There is a Tolkien page. There is a The Reading Order Calculator as well as Reading Order Facts page. It's quite a challenge to read Tolkien's stories in chronological order but here they have given you the indicators to do just that. Fascinating and mind-blowing to think about it right?
The Science Fiction Timeline Site is maintained by Larry King of the University of Washington. And is contributed by various other Sci-Fi junkies.
You've got to check it out.
The Science Fiction Timeline Site