TheReadingRoom.com and BookDaily.com are sites that offer a wide selection of free book previews of all genres. Amazon's Look Inside the Book program lets authors publish excerpts of books that readers can access online.
To preview books online using TheReadingRoom.com, hover over the link titled Free Books in the top navigation bar and select the Preview Chapters option. Browse the list for books or narrows down the choices by utilizing the search menu located above the book listings. A preview button is located to the right of each book. As of 2015, there are 7,877 pages worth of book listings with free reading samples.
BookDaily.com offers a library of books that contain small excerpts for each book selection. To view samples, browse by category or utilize the search bar to find a particular book. Categories are listed in the right column. After choosing a book, click on the book image. The excerpt is located in the description box and is titled Sample Chapter.
Amazon has a program called Look Inside the Book where authors and publishers choose to share samples of their literary works. Books that offer free previews have a "Look Inside" button located above the book image. This addition is not guaranteed for all books and cannot be narrowed down according to the feature, but the previews available for books that provide this feature are extensive.