Get the latest releases here.
Joomla Community -- community.joomla.org
Joomla Forum -- forum.joomla.org
Official Joomla Documentation -- docs.joomla.org
Joomla Bug Squad
Official Joomla Resources -- resources.joomla.org
Often referred to as the JRE
Joomla Extension Directory -- extensions.joomla.org
Joomla Idea Pool -- ideas.joomla.org
Joomla Developer Site -- developer.joomla.org
Joomla Magazine -- magazine.joomla.org
Joomla Mailing Lists
Joomla Website Showcase
A great place to get inspiration by seeing what others have done with their Joomla sites.
Also, if you have a great joomla site to show off this is a great place to post it.
Joomla Shop -- shop.joomla.org
no tour is complete without ending in the gift shop
ans we shall do the same.
Hope you found this post helpful.
Did I mill any online resources? If so post them in the comments and I will get them added to the post.