“You can also simply archive documents in your Kindle Library for re-download later. Your last page read along with bookmarks, notes and highlights are automatically synchronized for your documents (with the exception of PDF’s) across your Kindle devices and supported Kindle reading apps.” – From Kindle Daily Post
With a free download, you can send personal documents from your “PC, Windows Explorer, or “any Windows application that can print” to “Send to Kindle”. The app also gives you the ability to download multiple documents. Your archived documents can be accessed via: Kindle library, any Kindle device, or Kindle for iPod/iPad.
Fees may apply depending on the amount of storage.