Looking to change careers.

I will give you guys a little background on myself first. I was in the Navy for 4 years following high school, and upon getting out became a firefighter/emt for the Houston Fire Department. I am currently working on getting my bachelor's in fire science. I have about 2 years left on that. I will probably get a social studies endorsement on my teaching certificate. All I've ever wanted to do is coach high school football, but as you can see I've kept myself really busy. I would like to know what exactly I would need to do after getting my bachelor's degree to start pursuing coaching jobs. I've heard getting social studies or something other than p.e. endorsements on my teaching certificate really helps, and also heard that volunteering at a private school to gain experience really helps. I would really like to get the input of the guys who are where I want to be 3 years ago. I feel that my background and interpersonal skills would greatly benefit any program I work for. Thank you in advance.