Many high schools have youth baseball camps during the summer. Often, the high school coaches are involved in these camps and get to know potential players. It is always nice to be a "familiar" face but a surprise is good, too.
You'll meet more baseball parents from the area, I'm sure and you can get a better idea of what kind of players the coach looks for. Does he care if kids play multiple sports? Does the coach have a good summer league? What kind of baseball facilities does the school have? How much does the coach stress academics?
I don't know what I'd change if I had it to do over again. Ignorance is bliss sometimes. My son had to simply prove himself. That's character building.