One thing you will want to do when working with Joomla is to understand what Joomla calls certain things. You will in essence have to learn the Joomla slang or terms for certain things that you will work with within the Joomla program.

Now don't be alarmed this is not like learning HTML or Code.

Here is a quick study buide which will describe the Joomla features and in doing so will start to get you acquainted with what Joomla calls certain things within their system and what they do:
http://help.joomla.org/ghop/feb2008/task020/Joomla!%20Core%20Features%20V1.2.pdf