If you prefer to learn by watching, there are lots of useful videos on the WordPress.TV site, like the one above. This is an official channel run by the WordPress community and contains video tutorials on every aspect of managing a WordPress site. For beginners, I’d recommend you start on the ‘How to‘ section of the site.
Don’t forget there’s also the University of Lincoln Get Satisfaction service where you can ask and answer questions relating to the WordPress blogs, as well as documentation and videos here on this site.