The course role assignments screen is where I first got lost when using Moodle, and it is still confusing as it's the first place where breadcrumbs are necessary for navigation. The screen appears after a new user creates their first course, but there is no indication of how to get to the course you have just made at all, so those who are unfamiliar with the convention of using the breadcrumbs have no idea what to do.
"This screen allows you to add people to your course. Choose the role you wish to assign from the drop down and use the add button after highlighting them (use CTRL-click or SHIFT-click to add lots at once). When you are finished, go to your course page by clicking on the short name of your course in the breadcrumbs at the the top of the screen."