Of course, with many of these books being prequels to Frodo's story, it can sometimes be confusing to pinpoint a reading order. Those looking to get into Tolkien's Middle-earth works can choose ...
the twelve-volume History of Middle-earth (1983–1996), the three great tales of the First Age, as well as several books on various non-Middle-earth mythologies, such as on the Nibelungenlied ...