To view the courses you must register using the 

No account yet? Register

link at the top of the page.

You can then view the list of available courses under the Courses menu item.  

You must subscribe to a course to view it.

The previews are available at no charge so you can test your system. 

Once subscribed you may view the course as many times as you wish until the subscription period has expired. 

Some of the courses require the Microsoft Mediasite Silverlight player, you can download it for free at 

http://www.microsoft.com/silverlight/get-started/install/default.aspx