If you want to really understand how to make Joomla do what you want, it pays to understand Joomla's menu system. It is unique among content management systems, and is imbued with tons of power. Here's why:

So if you want to learn anything about Joomla, I'd highly recommend getting familiar and comfortable with the menu system. Play around with creating links, and see what sorts of changes you can make on the site. If you understand the menu system, you'll understand what makes Joomla tick.