Apple recently posted the iPhone User Guide for iOS 9 on iBooks.
Here's everything you need to know about iPhone, in a handy digital format. Get to know iPhone and discover all the amazing things it can do, and how to do them. It's the definitive guide for getting the most from your new iPhone from Apple. The iPhone User Guide is an essential part of any iBooks library.
The guide covers iOS 9 for the iPhone 6s, iPhone 6s Plus, iPhone 6, iPhone 6 Plus, iPhone 5s, iPhone 5c, iPhone 5 and iPhone 4s.
If you download it on the iPhone 6 Plus, there it opens in iBooks but very hard to read because the background color is black. Checking now to see if any way to change this since it's my first time to even open iBooks before.