A TechNet article provide overview of SQL Server Migration Assistant (SSMA) features and how it can be used to support database migration to SQL Server.
SQL Server: Manage the Migration describes the main feature area of SSMA including migration assessment, converting database schema, migrating data, and testing database migration. Read more in the embedd below. Or, if you prefer to watch video presentation, just watch the recording of the SSMA session at 2011 North America TechEd available from Channel 9:
Automating Database Migration to Microsoft SQL Server:
SQL Server: Manage the Migration article: