I purchased a book and it is on Adobe Digital Editions but I can not have my other devices to show up so that I can transfer the book to my iPad

What Adobe Digital app on your iPad? If you are talking about a third-party app (like Bluefire Reader) you need to connect your iPad to your computer, open iTunes, select the iPad, and select Apps in the Sidebar. Scroll down to the File Sharing section, select the app you plan on using, select Add (bottom right), navigate to where the book is on your computer, select the book and sync your iPad.

[discussion moved to Adobe Digital Editions forum]