There are many people who really want to learn and do better with Joomla! -I have seen many people who just wants to have some basic knowledge so that they can manage their websites in Joomla!
Here is a good link to quickly learn Joomla! using visual guide – please enjoy and thanks goes to Saurabh R. Bhide for his great work of preparing this visual guide.
Here is the link – Visual Guide for Joomla 1.5
This guide might not cover each and everything for you but at least gives you a good start and covers the basics too.