When you log into the Student Center, you'll see an overview of your current situation - enrollments, class schedule for the day, holds and tasks due, a summary of your current financial position vis-a-vis the University, and more. Just click on any link to drill down into that area for more information.
A number of PDFs are available on the main Student Center web page that will guide you through different aspects of the site and your responsibilities as a student at HSU; these are listed under the Student Center Tutorials heading.
The Student Center (and myHumboldt itself) is protected by a time-out period which logs you out of the application if you have not accessed it 45 minutes. You'll see a warning message before the system logs you out, at which point you can choose to stay logged in.
Think security when you log out of an application or myHumboldt and be sure to close your browser to fully quit or exit the application.