The most important thing about concussions and sport is that if you suffer a subsequent concussion before recovering fully from a previous concussion, it can lead to much more serious injury and death. The most important thing to do is identify a possible concussion immediately, remove the person from further concussive or subconcussive incidents and give them time to heal before they return to any activities that could do further damage.
Another factor related to concussion that is very important is that it is often the rotational forces that lead to concussions, not just linear accelerations. If you want to measure and thereby understand and prevent further concussions, you must measure linear and rotational forces in all three directions. Many systems do not do this, producing imperfect data.
There are many sources for concussion information. The information presented below is generally focused on athletes and responding to concussive events.
In no particular order, these links may be useful for those dealing with concussion.
Consensus statement on concussion in sport
(the 5th international conference on concussion in sport held in Berlin)
World Rugby welcomes the publication of a new consensus statement on concussion in sport