I want to know how to print a map in ArcGIS Silverlight application.
According to your question following will be the steps :
1) Create a new 'MapPrinterViewModel' class
2) Add two properties of type IEnumerable (lets say Graphics1 and Graphics2)
3) Initialize the MapPrinter.DataContext with an instance of this class
4) When it's ready, initialize Graphics1 and Graphics2 with the list of graphics that you want to see in your datagrid 1 and 2.
5) In your MapPrinter control template, bind the ItemsSource of your 2 datagrids to these 2 properties.
For Detail explanation check out ESRI forum link
Eventually i found a good video about advanced topics including [printing map]