There is a significant amount of material in this course. You will not be able to consume it in one sitting. You will also not likely need to consume all of it. We have striven to be as complete as possible in providing this tutorial material for you, therefore the level of information is much higher than what is necessary to do daily tasks on your site. It is therefore recommended that you watch the Welcome section, the Finding Your Way Around Wordpress section and the Working with Content section. These will give you a basic understanding of the various functions of Wordpress. After that, begin working with your site, and use these tutorials as reference when you need to know how to do something specific.
The Quickstart Tutorials are also good reference material as they quickly go through basic tasks on your site, but have minimal explanation. They will show you the basic steps for completing a task without an explanation of what every blank and field does.