Microsoft is distributing a nice – MS SQL Performance Dashboard which you can use in the SSMS and SSRS.
MS SQL 2008 / 2012 : http://www.microsoft.com/en-us/download/details.aspx?id=29063
Getting Started with the Performance Dashboard Reports in SSMS
1. Each SQL Server instance you plan to monitor must contain the procedures and functions used by the queries in the reports. Using SQL Server Management Studio (SSMS), open the Setup.sql Script from your installation directory (default of %ProgramFiles(x86)%\Microsoft SQL Server\110\Tools\Performance Dashboard) and run the script.
Close the query window once it completes.
2. In the Object Explorer pane in SSMS, right mouse click on the SQL Server instance node, then choose Reports-Custom Reports. Browse to the installation directory and open the performance_dashboard_main.rdl file. Explore the health of your server by clicking on the various charts and hyperlinks in the report.
All of the remaining reports are accessed as drill through operations from the main page or one of its children. For a detailed explanation of all installation requirements and guidance on how to use the reports, please see the help file, PerformanceDashboardHelp.chm.
Once installed you can also use it inside of the SSMS – Browse to %ProgramFiles(x86)%\Microsoft SQL Server\110\Tools\Performance Dashboard folder and open the performance_dashboard_main.rdl report.
Getting Started with the Performance Dashboard Reports in SSRS
To get it to work you need to run the SETUP.SQL query in the Master DB. Copy all files from the install directory to your SSRS reports directory. And upload them to the SSRS Reporting Portal.
Create a Shared Data Source in the Report Server !
Once the reports are using the correct data source you can run the main Report to test it.
SharePoint Database Health Dashboard – Bonus
If you are running SSRS in SharePoint Integrated Mode, than you have a nice interface to monitor your database Health.
Just publish the SSRS report to a SharePoint library
And there you go all the data is available per content database.