Click on the "purchase" button just above for the free sample.  You will be taken to a check-out page, but there is no charge and you do not need to provide any payment information.  Fill in your snail mail and email addresses (the snail mail address will not be shared or used, but the check out page requires it even for free items).  The price will show as zero on the checkout page.  Leave the credit card information on that page totally blank, and "purchase" the sample.  Within a minute or two of your "buying" the free sample, you will be emailed a link to download and play the sample, as well as a separate email which is a receipt showing the price as zero.  The sample, like the Audio Book itself, is an Mp3 file that can be played on computers and other digital devices, but the link is only good for 24 hours so be watching your email and make sure you have provided an accurate email address.  Both the receipt and the audio link emails will come from DoctorinBlue.