My Favourite writer (in any language) is Carlos Ruiz Zafón, author of La Sombra del Viento, or The Shadow of the Wind amongst other novels. His website, www.carlosruizzafon.com is a great resource with plenty of free stuff to download in the 'Descargas' section, including first chapters of all his novels. My favourite part is 'Relatos' where you can download a selection of unpublished short stories featuring the trademarks of Zafón's longer works - dark plots and Gothic settings in his native Barcelona.
Also available to download are wallpapers, videos and music. As expected the site also hosts a lot of information about the author and his books, including a mini site for each of his novels.