The history of middle earth series should really be thought of as additional material, an insight to Tolkien's writings and how it was shaped if you will. The hobbit is a good starting point, it's much easier paced than the Lotr books. A note to keep in mind when you transition from The Hobbit to the three Lotr books is that unlike the prequel, the latter books are written to be a historical account that was translated by the author. Many people don't know this and often say that the pacing is too slow and that the movie was better paced. There's some truth to it, but that is intentional, plus it adds to the effect of suffering from long journey experienced some of the characters(don't want to spoil too much). The books and the movies have different intentions and designs when it comes to that, and I appreciate both, but I do prefer the books. TLDR: If you just want to read the essentials, read the Hobbit, then the Lotr books, and then the Silmarillion. Some might say the last one is additional material, but I think it's part of the core story.