I published a post the yesterday on how to sell your digital downloads through an online service which takes care of everything, from payment to delivery of the items.
The service is brilliant for practically anyone who has a blog or website and wants an external source to take care of everything.
However it isn't free, you're charged on a monthly basis, even if it isn't much. If you're looking to sell your goods for free and you have a Wordpress site, you're in luck.
Paid Downloads is a plugin which allows you to sell your digital downloads through your Wordpress site, completely free of charge (PayPal fees still apply).
The plugin is one I actually use myself on this very site to sell some of my digital downloads. It's very easy to set up and is very customisable. You can do things like customise emails, use your own buttons, have your own terms and conditions, set the lifetime of a download link...etc.
The plugin allows you to sell as many files as you like and you can use as much storage as you like, depending on how much you get with your hosting.
You can then use simple shortcodes to place buy now buttons in posts - making it super easy.
I highly recommend it if you use Wordpress and are interested in selling your digital downloads.