I plan on using calibre to sideload my books onto my Kindle when it arrives. I have bought a few books and have downloaded them using the Kindle for PC app. I then opened up calibre and added the books (I found them in my C:\Users\Dwayne\Documents\My Kindle Content folder). calibre seems happy to import them into its own library and it allows me to change the author's name to last, first as well as amend the title to indicate series books etc.
Now all I need is my Kindle so I can load them up!