As long as you are a system admin in Salesforce, you will be able to add mini components to your home page layout(s).
First, go to Setup in Salesforce. Then Customize > Home > Home Page Layouts. You can also search Home Page Layouts in the Quick Search.
Choose the Layout you would like to add the mini components to, and click Edit. Check Scorecard Mini and Mini Leaderboard.
On the next screen, you can choose where the mini components will sit. LevelEleven recommends at the top - Scorecard first, then Leaderboard.
And to make sure mini components are on all pages, go to Setup > Build > Customize > User Interface > Show Custom Sidebar Components on All Pages.