Odds of Getting In
If coaching high school sports is your dream, then here's some good news for you—this career field is projected to grow by leaps and bounds in the years to come as more and more kids enroll in high school and (theoretically) enter the wonderful world of competitive team sports. Moreover, at most schools you just have to want a coaching job in order to get one.
Finding a job as a college coach may prove a little harder, depending on what sport you want to coach and where you want to work. If your goal is to run the swim team at a small liberal arts college in the Pacific Northwest, then you won't need much more than a bachelor's degree and minimal experience as a swim coach to land the gig.
If your goal, however, is to take the Crimson Tide to another BCS victory, then your path is going to be more complicated and, honestly, the chances of coaching football at a football university are slim.
As for coaching a professional team, look at it this way: There are thirty-two head coaches in the NFL, 30 MLB managers, and never more than thirty head coaches in the NBA. In other words, there are a handful of these jobs in the United States. Your chances of getting one are pretty much nil.