The BlogCastRespository is a great community resource that's available for you to learn from other people's experience of the best way to use software. Being a community resource you are able to sumbit your own demonstrations too.
To view the extensive list of free blogcasts simply browse to the BlogCastRepository. To view the blogcasts themselves you need to register - this is free of charge and you won't receive SPAM or sales contact as a result. To register simply click on the "join" button (located at the top right hand corner of the screen) or click here.
At the time of writing this post there were 153 blogcasts on the site covering topics such as Windows Server 2003 Release 2 (R2), SQL and Exchange Server together with a wealth of other interesting topics.