What are good prep school that are boarding, that can prepare me to become a human resource person?

I would suggest any good Business School. There are many HR specialties (recruiting, compensation, employee relations, org development...) but in order to be a generalist or an effective business partner it is helpful to understand business and how to support the business through HR processes. In addition to standard colleges there are many certifications (i.e. PHR,Professional in Human Resources) and ongoing training seminars that keep HR professionals in tune with new laws or changes in the field.