You no longer need a
Head to the Nook for Web page on the Barnes & Noble site and you can immediately sample these six titles:

Click on a cover, and a sample containing the first few pages will open in a new tab. To read past the sample pages, you will need to add the book to your library. To do so, click the Nook Book button in the upper-right corner when viewing the sample.
The six titles are free of charge, but before you can add one to your library, Barnes & Noble forces you to sign up for an account, which entails providing a credit card number, billing address, e-mail, and phone number. If you are willing to hand over such information, the book is instantly added to your library and available immediately. You are not downloading the book, mind you, meaning you will need Internet access in order to read it.
When you have a book open in your browser with Nook for Web, there are six buttons located in the upper-right corner to adjust your view or access additional information. From left to right, these buttons let you access the table of contents in a small pop-up window; adjust the font and font size and choose a single-page layout; rate, review, and recommend the book; view a summary of the book and other books like it; enter full-screen mode; and enter simple view, which hides these controls.
Above these six buttons are two links: my library and shop. You can use the my library link to view your purchased titles and the shop link to explore the Nook Book Store.
Nook for Web supports Internet Explorer, Chrome, Firefox, and Safari. The company says support for the iPad is coming soon. And sure enough, when I tried accessing one of the Nook for Web samples via Safari on my iPad 2, I got this message: