This is my cv as pdf.

The customer can click add to cart button and the item will be added in the shopping cart on the left. Once "Checkout" is clicked, user will be sent to PayPal to complete the transaction. 

Once the customer paid for the files in the shopping cart, he will be able to go back to the website and download the files that he paid for.

This will work with various file types, but for .PDF there is also a "Preview" feature that can be turned on to allow the user see the first page or two from the document.

You can also turn on the "Encrypt PDF" feature, and all PDF files you sell will be encrypted so the buyer can't share them online on torrent or other file sharing sites. The password always is the buyer's PayPal email he used for payment, so you can easily track down the pirate.

This is just a sample file to show that you can also have free downloads. Payment is not required for all files.