Reddit reviews Nietzsche: A Very Short Introduction

>Just to clarify for myself - you are talking about those books that explain the core concept of the book before the actual book begins, right?

Yes, definitely. It's even better if each section of the book gets a mini-introduction, given how complex the whole book will be, but that'd be hard to find - sometimes there are commentaries, but not always. Both of those books look great, too! But I would definitely do some background research on the internet to see which Nietzsche secondary sources are best/most recommended by the professionals; check the recommendations in the SEP article, for instance.

>Do you think I should only get one of them and then as a second book a book by Nietzsche with that introduction by someone else that explain the core idea briefly?

The Nietzsche Reader has big chunks of each of Nietzsche's main books in it, so you wouldn't necessarily need to buy the books again (unless you were really keen on reading every line). I haven't read the other one but it looks great too. However I don't think it has primary material; it looks like a new philosopher's take on Nietzsche, one reacting to Heidegger's old interpretation. I personally prefer The Nietzsche Reader as a book to first introduce you to Nietzsche, since it has short expositions followed by primary material, and then you could move onto the revisionist interpretation one - but again that's only 'cause I used the Nietzsche Reader myself so it might just be bias lol.
Even better, you might be able to find a simpler introduction, one that sticks to the main ideas, depending on how much philosophical knowledge you already have.

At the end of the day, my advice is definitely to find a good (relatively simple) intro book if you haven't read Nietzsche before - that is essential. (Without a companion reader, reading Nietzsche is like reading Kant, Husserl, Heidegger, or Wittgenstein, in other words the hardest and most technical and/or obscure writers, so background is essential). Then I would pick specific primary texts based on what you find you like.

EDIT: I found [this one] (http://www.amazon.ca/Nietzsche-A-Very-Short-Introduction/dp/0192854143) online. Also, I think Walter Kaufmann was one of the biggest Nietzsche scholars so you could check out his work. And depending on your budget, you might just want to read the SEP article; that is a fantastic intro to Nietzsche's work from what I can see.

One book that is popular to help understand Nietzsche is Walter Kaufmann's Nietzsche: Philosopher, Psychologist, Antichrist. It usually comes up on this subreddit when people look for secondary texts on Nietzsche.

One dis-recommendation I would make is Nietzsche: A Very Short Introduction by Michael Tanner. The Oxford University Press "A Very Short Introduction" series is usually excellent, but I was not impressed with this particular title. It was the first book on Nietzsche that I read and frankly I found it pretty useless.