What components should be addressed in a new employee orientation to ensure that an employee understands the style/culture of the new organization.

Each organization has its own style and its own culture. Hiring new  employees and bringing those employees into the organization can be a  challenge, especially when new employees have worked for a company with a  different style and outcome. Specifically, What components should be addressed in a new employee orientation to ensure that an employee understands the style/culture of the new organizatio. and how best can  this be explained/discussed with the employee in his/her first days of  employment?