How do non administrators add content?
You probably don't have the Navigation menu enabled/placed in a region, or have any other links to direct a user to the Create Content page.  

As an administrator, either enable that menu or create a link to "node/add" (to allow the users to see all the content types for which they can create a node); you can also add a  link to "node/add/article" in another menu or in your theme.

To allow a user to see the administration toolbar, they must have a role that has the permission to use the administration toolbar. See below: