There are many sites that offer free ebooks in Spanish, including MultilingualBooks.com, Español.FreeEbooks.net, Amazon.com, LoyalBooks.com and Bookrix.com. These sites allow users to download ebooks from different genres and in different file formats.
Amazon.com has a Kindle Store that has a Spanish section under Foreign Languages. Many ebooks in the Kindle Store are not free, but there is still an impressive collection of free Spanish books. Customers can use the Sort By dropdown menu on the upper right and select Price: Low to High. This shows all free ebooks in Spanish first.
MultilingualBooks.com has free Spanish ebooks available for download, and it also contains links to other collections of ebooks such as the Anthology of Spanish Poetry, Proyecto Cervantes and Proyecto Ensayo Hispanico.