NOTE: This is to be done after you've created a Database and I won't go into details as to how to create a Database or how to add a user to the database.
I retrieve info from MSDN TechNetabout the database roles and are as such.
|Database-level role name||Description|
|db_owner||Members of the db_owner fixed database role can perform all configuration and maintenance activities on the database, and can also drop the database.|
|db_securityadmin||Members of the db_securityadmin fixed database role can modify role membership and manage permissions. Adding principals to this role could enable unintended privilege escalation.|
|db_accessadmin||Members of the db_accessadmin fixed database role can add or remove access to the database for Windows logins, Windows groups, and SQL Server logins.|
|db_backupoperator||Members of the db_backupoperator fixed database role can back up the database.|
|db_ddladmin||Members of the db_ddladmin fixed database role can run any Data Definition Language (DDL) command in a database.|
|db_datawriter||Members of the db_datawriter fixed database role can add, delete, or change data in all user tables.|
|db_datareader||Members of the db_datareader fixed database role can read all data from all user tables.|
|db_denydatawriter||Members of the db_denydatawriter fixed database role cannot add, modify, or delete any data in the user tables within a database.|
|db_denydatareader||Members of the db_denydatareader fixed database role cannot read any data in the user tables within a database.|