How do I enter an employee and his/her career information ?

When setting up the OM Staff software, you enter a record for each of your employees in the Employees file, accessible via the Data menu. Call up the Action>Add command to create the record.

The page accessible via the Career tab contains various fields to describe the employee's career: Entry date (mandatory), possibly Exit date, Occupation, Department, Function, History of various positions held and corresponding salaries, etc.