So, apparently, CHC is the only real institution worth sending your son for baseball--gimme a break. They do have a historically strong program. However, all I can say is, I hope he's a stud. Otherwise, he will simply sit behind the better player for four years. Maybe not the ideal H.S. experience.
There is some good ball in Howard County, I wouldn't say the league is anything extraordinary from top to bottom. There are also several good schools and private schools in Anne Arundel. However, no one should deny that the MIAA is the most competitive HS league from top to bottom. CHC, Mt. St. Joe, Loyola, Spalding, Cardinal Gibbons, and even Curley all have strong programs this year.
Summer Ball is a different story. There are competitive teams everywhere. Typical Howard County programs that are usually decent include HCYP Raiders and WHC Renegades, to just name a couple off the top of my head. Good luck.