The first important thing for writing any kind of essay is to formulate an adequate question you want to address in the essay. What do you want to demonstrate? Why is this question interesting and why is it important? This question should then be included in your introduction.

The introduction of your essay should not only address the research question and the argument you propose, but also the structure of the rest of the essay. What will you do in each section of the essay and how are these sections connected with each other? You will experience over the writing of an essay that the introduction changes over the course of the writing process. You will add and delete certain aspects of your introduction, or you might even re-formulate parts of your question and your argument.

An example for such a question in the context of a book analysis might be: Inwiefern stellt das Buch ein Beispiel für einen Text aus der Epoche der Romantik dar? Welche sprachlichen und stilistischen Mittel verwendet der Autor/die Autorin, die auf die Epoche der Romanik hinweisen?

In order to elaborate on this question, you might give a short overview of the structure of your essay and your methods: In einem ersten Schritt werde ich die sprachlichen und stilistischen Eigenschaften der Romanik darlegen, um sie dann in einem zweiten Schritt auf das Buch anzuwenden.

This structure enables you to outline your argument and the approach you will undertake in order to elaborate on the same.