You can create your own library on Zotero
Zotero The quickest and easiest way to create a library compatible with Office Word.
Mendeley Easily organize your papers, read & annotate your PDFs.
Google Books You can create your own library and add book reviews and ratings.
Scribd Read millions of documents and books, download, print and send them.
Calibre The one step solution to all your e-book needs.
Kindle More than 1 million kindle books on your PC.