This is the day that you can save yourself many hours of management time and many thousands of dollars. If any of your policies are not followed, day one is the time to address it. For less critical things let them know exactly how it should work and make it crystal clear that you expect them to follow your rules. For more critical things – for example, showing up late – tell them emphatically that this is unacceptable and consider this to be their first warning. If you let things slide because you don’t want to get into a conflict right off the bat, then you can plan on constantly getting into conflict with this person on the things you let slide for as long as they work for you.