In my opinion, Shopify, Wix and 3D Cart are considered very reliable e-commerce sites that help you a lot to set an online web store. However, if you are planning to sell or deliver digital products including ebooks, downloadables or internet marketing services, then you should get the shopping cart widget of https://getdpd.com/. Yes, I am using DPD to sell my DIY videos and whiteboard animations. It is serving thousands of web stores and very secure to use.
What type of small business are your running, Peg? Are you going to set up a dedicated website for your business or are looking to go through a third party platform?
If you're going the dedicated website route:
Many small business owners -- including myself -- use Wordpress. It has thousands of plugins that you can add to your site to customize it, including several for e-commerce.
I personally love Squarespace it's the platform I use for both my blog and my shop. It's easy to use and pretty straightforward. It's less than $40 a month.
Hey it's Me Shanie -Blogger Extraordinaire.