The widgets on your main Dashboard allow you to get a quick glance at the various components of your installation, view recent activity, as well as make announcement posts for your various users.
You can easily drag-n-drop the individual widgets into a layout you like, as well as set default layouts for all of your various user roles in your SuiteDash environment. To get started editing the Dashboard layout, just hover over and click the pencil icon on the right side of the page.
From there, you can grab any of the widgets you are not using from the top-left, and drag them down into your Dashboard to get the layout you want.
In the same area, you can use the "Edit Widgets" dropdown to select a particular role, and edit the default layout for that role in the same drag-n-drop fashion. When finished, just click the "Save" button on the left side to save your changes, then refresh the page to see your new Dashboard layout.