While youre in Settings, also consider removing any email or calendar accounts still saved in the Mail, Contacts, Calendars section; if this iPad is for reading, theres no sense letting those apps gobble up extra bandwidth and battery. And if you havent already, under General, ensure that the Side Switch is set to Lock Rotation and not Mute; youll need the former option far more often if you move around as you read.
Which apps you need
Put bluntly: Get the apps you need to read the content you want. If youd like your dedicated e-reading iPad for books, grab Amazons Kindle app and Apples iBooks app. There are plenty of other e-reading apps; unless you already own books for another platform (like Kobo or Nook), theres no need to pursue those.
Devoted Kindle readers may also want to install the Kindle Cloud Reader Web app; it integrates the Kindle bookstore directly, which the App Store app isnt allowed to do. Alternatively, you could stick with the iOS app and simply install the iPad Kindle Store Web app instead.