Oak Brook carefully selects staff from many applicants by using a two step interview process. References, FBI background checks, and fingerprinting are done prior to hiring. All teachers are required to have current CPR and First Aid certification. Teachers with less than 2 years of previous experience must complete a 24 hour pre-service training. All teachers are required to attend a minimum of 24 hours of additional training each year that is relevant to the age group they teach.