I will take you through a step by step process of creating a website using the open source content management system, Joomla. A Content Management System (CMS) is basically a software package which gives you a way separating the content from the view giving you more flexibility and ease of operation and maintenance. It also provides an easy to use framework to add and publish content to your site. In some ways it is similar to Wordpress but is more advanced and gives a lot more options both for view and content management.
If you need more information on what a CMS is, you check out the Wikipedia here.
Joomla is an open source CMS which lets you create and maintain content as well as publish it in a very effective manner.
Joomla separates its content and view and there by gives us a lot of flexibility to work with and more importantly make it very easy even for a beginner.
Here an article from the home page of Joomla with more information about it.