How can I become a football coach?

If you don't ease into coaching by virtue of playing -

you can get a college degree in Coaching.

You can also start by volunteering with the local clubs whether they are pop-warner, the Y, high school, or even semi-pro.

You won't be implementing your own defense: but you will be drawing valuable coaching experience and learning the mechanics of what it is that you love to do.

It isn't easy. I coached for a few years but work got in the way.

-Go to a local high school/Middle School and talk to the A.D.

Tell him you are interested in coaching and would like to start out as an assistant (doing anything, for free). You have to pay you dues. You may get a few "turn downs", but schools are always looking for some help.

P.S. Get a degree in teaching if you want to make a career out of it.

Like others have said, go to a HS or middle school and volunteer as a low level assistant to get your foot in the door. Go to clinics, read books, ask questions of every coach you can. Don't be afraid to speak up. You have to put in your time in the lower levels. Don't expect to start at the top and don't be picky about the first job.

Go to your local Pop Warner team or high school and volunteer. You may not get a job your first time around, but there will be a place willing to give you a shot.

After that, you have to pay your dues and network.