Buy or obtain the Kindle book from the Kindle Store or a supported source
Sign in to the same Amazon account on your Kindle device or Kindle app
Connect your Kindle to Wi-Fi
Open the Kindle Store on your device or app
Find the book
Select Buy Now or Download
Wait for the book to sync to your Kindle library
On your Kindle device, open Library
Tap the book to download it to the device
If using a computer, go to Manage Your Content and Devices on Amazon
Select the book
Choose Deliver or Download and transfer via USB if needed
If the book is from another source, send the supported file format to your Kindle email address or use Send to Kindle
Sync your Kindle after sending the file
Open the book from your Library after the download completes