The NFHS Learning Center offers the free online class "Concussion in Sports - What You Need To Know".  It looks at different aspects of concussions such as what a concussion is, how to recognize a concussion, and the issues involved in returning athletes to the classroom and to sports.  

Now a requirement for coaches, the course is also suitable for is athletes, parents and teachers.  Sign-up is required and you can expect to spend thirty minutes going through the course.