I know a variety of languages and am always trying to learn something new. I thought it may be good to tackle Joomla! Template Programming to start as I know Wordpress and this would be a great skill to have. I went through a basic Joomla! Programming but it really just lays out how to make it. Is there a good resource to go through how Joomla works and template programming for it?

From Beginners to Advanced Tutorials/resources if there are those. And is there a secret to Joomla! Documentation i'm not understanding?