Here are several links to free online concussion courses to educate yourself. All paid and volunteer coaches are required to obtain yearly education on concussions. Any of these course will satisfy that requirement.
1. NFHS Learn Course:
http://www.nfhslearn.com/electiveDetail.aspx?courseID=38000.
2. Concussion Wise Course:
http://concussionwise.com/for-coaches