I would think most coaching positions would be filled for this summer. Many start out in coaching as an assistant at their former college. It can be difficult financially, but not many decent paying jobs in the beginning. Probably the quickest way to move up the ladder is to show ability to recruit. Those that prove they can recruit are in demand.
He should make a short list of the most influential people he knows in baseball. Those that know him are the ones that can help him the most. Unfortunately, this is another Who You Know thing.
The topic of minor league players not being compensated fairly was popular here. Starting out in coaching can be much the same way, just not talked about as much.