There are numerous ways to load ebooks on the brand new Amazon Kindle Oasis. You can borrow ebooks from the public library and have them automatically sent to your ereader, well as long as they use Overdrive. Each Kindle is is assigned a unique email address and you can email docs, pdfs and MOBI books directly to your library. This is useful for people who are at home, work or commuting and want to send over a bunch of books so they can read them later. Calibre is a really comprehensive program, it allows you to better manage your sideloaded collection, it allows you to convert one ebook format to another, change the cover art, add an ISBN numbers.