A good place to start would be the New Zealand Department of Labour at http://www.dol.govt.nz/ .

SFBay is right. SOX does not require you to insitute timekeeping for exempt employees, although some employers do require exempts to keep track of their time. SOX requires you to have procedures in place to prevent unauthorized payments.

Make sure you know your state law in this area. Some states require advance notice to employees before you monitor their activities. In any event, having a policy stating that computer use may be monitored is a good idea.