title_body: Which software should I use to manage all my books and collections in my Kindle?
upvoted_answer: I like to use Calibre to manage and convert ebooks. You will need Kindle's software for PC in order to download the books, that you can then import on Calibre.
  
  Beware that the books are DRM protected, so you won't be able to convert those.
  
  It is free (both as in '..speech' and in '..beer') and actively maintained.