A recommended guideline is to meet with a new employee once every 30-60-90 days, but this may be more or less depending on their skills and confidence levels. Too often and it may seem like overkill and unnecessary. The main focus is to ensure progress, understanding of their role and to see how they’re tracking against their performance expectations and training plan.
A manager should document the discussion points after each meeting with their new employee, noting the progress against plan. This documentation will be helpful for later performance reviews or if it becomes evident the job is not a good fit for the employee.