Manage Your Kindle doesn’t list docs that you load to your Kindle Fire using the micro-USB cable (a process known as sideloading). Docs that you see listed in Manage Your Kindle have been emailed to your email address for document conversion.

ebooks that you have purchased from a source other than Amazon appear in the Personal Documents content library. Ebooks that you have purchased from Amazon’s Kindle Store appear in the Books content library.

You can also transfer them to your Kindle. You can view all the books and documents in your library using Manage Your Kindle. Finally, you can register and deregister Kindles and rename your devices from the Manage Your Kindle page. Links enable you to manage your method of payment to Amazon so that items you purchase on your Kindle Fire get charged to the right credit card. You can also use it to see the periodicals you subscribe to, and you can manage those subscriptions as well. You can use the Manage Your Kindle page to send books from your Kindle library to any of your Kindle devices. If you have multiple Kindle devices, the Manage Your Kindle Page is even more useful. Amazon’s Manage Your Kindle page is a one-stop location for managing your Kindle content and your Kindle device.

Send to kindle registering message