Where does the Kindle app store the books that are downloaded to the Surface and is there any way to have them save and stored to the SD card? I though to had seen a post about saving files stored by apps to SD card but can't locate it now.
C:\Users\<userid>\AppData\Local\Packages\Package Name. For Kindle App Package Name is AMZNMobileLLC.KindleforWindows8_something something = stfe6vwa9jnp for me but it might be different for you. After that it should be in either LocalState or Roaming State or SystemAppData
it appears that books being used by the Windows 8 Kindle app are being stored in the cache folder. Each book has been broken up into .fragment (eg. 1.fragment, 2.fragment, 324.fragment, etc.) files. I have no idea how it takes the .fragment files and generates each page of the book. But, I imagine they did it this way to reduce loading time for each page.