You can also use an all-inclusive ecommerce web service. Sites such as Shopify and Volusion offer competitive packages, with free templates, custom packages, credit card processing, and more. Ecommerce web services makes it easy to sell your products on the web, without a lot of overhead. There are no custom interfaces or templates to work with; you simply create an online store within the framework of the service.
Many of my readers have started proofreading from their iPads, scanning legal documents for court reporters as a result of the Proofread Anywhere eCourse I recommend. You can read some of their testimonials in the comments on this post. They offer a 7-day intro course free so you can decide if that line of work is right for you before you pursue the training.