Criar um novo usuário db no SQL Server 2005

CREATE LOGIN [user] WITH PASSWORD='password', 
       DEFAULT_DATABASE=[your_db], CHECK_POLICY=OFF
GO

CREATE USER [user] FOR LOGIN [user]
EXEC sp_addrolemember N'db_datareader', N'your_db'
EXEC sp_addrolemember N'db_datawriter', N'your_db'
GO