Excellent question. I'm guessing you'll get a thousand answers because I think you'll learn that everybody does things differently which is one of the strengths of this site. Your son is on a good travel team which is a good thing for starters.
First, when my oldest son was your son's age it became very apparent to us that youth baseball was ending and big boy baseball was starting. My son wanted to play at the highest levels and work with pitching coaches to learn & develop. So, that is what we did. We were very fortunate that he is a very focused individual and knew what he wanted. There were trade-offs with the new travel team, and he had to earn his spot and playing time.
Second, we studied and researched what it took to play college baseball from an athletic standpoint and academic. My son kept a very watchful eye on older players in our high school district and older players from our travel team organization. He paid very close attention to where they were going, how they got there, and what it took to get there. He asked a lot of questions from his coaches. Typically, we have anywhere from 6-12 players in our district per year headed off to D1 schools. We went to some college games, and he attended some camps when he was younger. I think this gave him a lot of perspective about what it took. Everytime we were on the road going to a travel tournament, we'd make time to stop in to see a college or two.
Third, he played Fall travel baseball every year. This is when he'd work on new pitches or pick off moves. He worked out in the Fall & Winter, and got into very good shape through running, training and weight lifting. He made the JV high school team in 8th grade. Practiced every day and learned other positions such as outfield or 1st base that he rarely got to play on his travel team as a pitcher-only. I saw the biggest improvement in his game when he made the JV team as an 8th grader. He was working his butt off and it showed. He would bug me to take him to the baseball field on the weekends to shag balls and work on ground balls. He looked at high school baseball as the stepping stone to his summer travel baseball season. His travel team was very successful, and gave him a lot of opportunity for exposure over the years. This would open the door for future college opportunities that would be considered.
Fourth, he continued to focus on academics, and learned excellent study habits. This will come into play in the junior and senior years in high school. Junior and senior years are brutally stressful because you have SATS, drivers ed, visiting colleges, recruitment, AP classes, dual enrollment, athletics, etc.
Five, HSBBWeb. The answers are all here electronically or in the heads of our members. You just have to ask the right questions.