Setting the Dashboard for the Home Tab
You can choose any dashboard you have access to as the one that appears on your HOME tab.
Only the top three components of the dashboard are visible on the Home Tab.
Click on "Customize Page" to change the dashboard that appears on the Home Tab
You can then choose to show data from any dashboard you have access to:
Click on the picklist and pick the dashboard you wish to have appear on your home page. It will replace the one that was there by default.
You can change the dashboard you're monitoring on your homepage as often as you like!
Don't forget to hit REFRESH to get the latests dashboard data.