I have multiple articles relating to different system guides; there are loads of clients on the Joomla system that will need to view them, but I want each user to see only what they should and not all of it, some of them will have articles specifically relating to one then the other. Is there a Joomla feature or extension to help out, please?
You can try this extension : http://extensions.joomla.org/extension/acl-manager
But, better would be if you set permission based on user-groups, rather than users.