From Joomla! Documentation
Help with Joomla! 1.6
For help with a specific page within Joomla you can click on the help toolbar icon for further information about that specific page.
If you have only recently starting working with Joomla you will probably have experienced the pain of learning a new system. New terminology, new ways of doing things, perhaps even the web itself may be new to you. Then let these guides relieve some of that pain.
Further information about Joomla! 1.6
Any users on Joomla 1.6 should upgrade to Joomla 2.5 immediately as there are known security risks and bug fixes in 2.5. There will be no backwards compatibility issues if you make this upgrade from 1.6 to 2.5. For more information see the Joomla 1.6 category page.