Windows Phone 7

IMPORTANT NOTE: Effective January 4, APIDs will be assigned for each new placement in your apps & mobile websites. For existing placements, no action is required. For new apps & placements, we will provide an APID for each placement and you’ll simply need to include that APID in your apps. Learn more here.

Select the appropriate SDK for your application type - Silverlight or XNA

You can find instructions for the Silverlight SDK here.

You can find instructions for the XNA SDK here.