Your dashboard is the first page you come to when you log in.
The dashboard has the following "widgets" on it:
Todo list - If you have this feature enabled, you can create reminders for yourself.
Member engagement - This lists stats from your discussion forums. You can turn this widget off on the "Setup > Club Details" page.
Revenue - If you have access to view invoices you will see a monthly breakdown of your paid and unpaid invoices.
My calendar - This shows any sessions you are assigned to and also allows you to add availability, for example, when you go on holiday, you will be marked as not available for any club events that happen between those dates.
You can move widgets around by dragging and dropping them, as well as changing the header colour.