Newcomers to Joomla often find it difficult to get to grips with the way the 
CMS organises data and content, even though once you figure it out it's as easy as pie.
It doesn't hurt, however, to have some good guidance like a quick start guide to get started on the right track.
Amy Stephen, who I believe is a member of the Joomla core team, has put a slideshow of the quickstart guide up for Joomla users.
Check out the Joomla 1.5 Quickstart Guide slideshow on Slideshow here...