We regularly publish content of interest to Joomla users. Some recent articles are:-

Understanding CSS Selectors When Editing Joomla Templates - a short guide to some of the pitfalls of editing template css (and how to avoid them)

Joomla Password Security - how to protect your Joomla administrator password

Social Networking Extensions for Joomla - a review of social networking extensions for Joomla

Subscription Components for Joomla - a review of paid subscription components for Joomla