Most people are tempted to start with a quote; I would strongly advise against it. You only have a certain amount of space to spend discussing literature, so start off immediately by talking about it, straight from the first sentence.You can incorporate quotations later, wherever relevant. In your introductory beginning, discuss what it is about literature that sets it apart for you. Later on, you can show why you're suited to the subject, but start off by talking about why it is important to you. Avoid clichéd beginnings that talk about how you've always loved reading; discuss what it is about literature in the here and now that makes it special rather than your nostalgic bond with it.