Note: It's OPTIONAL to create an Adobe ID. The benefit is that you can login to your Adobe ID from any device with Adobe Digital Editions and view the content associated with your ID. If you only plan to use it on that device, you can skip that part of the process.
If you have an iPhone:
If you have an Android device:
You can also get to these apps from the Adobe Digital Editions website. Once you've installed the app, you can download the ebook on your device. If you want to create or login to an Adobe Digital ID, you can view the same ebooks across multiple devices.