Documentation:
Official Joomla Documentation Wiki
http://docs.joomla.org/
 
The Absolute Beginners Guide to Joomla!
http://docs.joomla.org/Beginners
 
Joomla Frequently Asked Questions
http://docs.joomla.org/Category:FAQ
 

 

 
Useful Links:

 

 
Training:
Joomla! Days Directory
http://community.joomla.org/events/joomla-days....
Local communities worldwide organise Joomla Days. A Joomla Day is an event created exclusively for Joomla users and projects and usually draws a regional audience.