A few questions for you. What grade is he currently in? Junior? Senior? Has he taken the ACT/SAT yet? Scores?
A 3.0 GPA, while good, is not exactly stellar.
Have you investigated any of the NJCAA schools that he may attend? Are they "local"? Keep in mind not every junior college or community college has teams in the NJCAA. Our local community college doesn't. Many don't have student housing so if the student is from out of the area they'll have to find their own housing. In my son's case the coach was good about pairing up players from out of the area and the school had a good relationship with many apartment complexes. If your son has to have housing figure on an additional $6,000-$8,000 for housing, food, gas, etc. And that's on top of the tuition/books.
If your son is a senior this year, fill out the FAFSA as soon as you can. When it comes to any available grants, the early bird gets the worm applies here. Some Juco's don't participate in the federal student loan program, but there could be state grants/loans available. In my son's case PHCC had dropped out of the student loan program, but he did qualify for a Commonwealth Grant that covered most of his tuition(95%). At that point we just had to cover books and housing.
As far as baseball goes, I'd recommend checking the schools out via the NJCAA website (NJCAA.org). Find your region. NY is split into two regions (3 and 15). There's 23 schools listed that participate in DIII NJCAA baseball. You want to find a successful program. Usually there's a correlation between small rosters and poor records (sometimes not). I would suggest visiting the schools and taking in a few games. See how the coach manages the players. Arrange a meeting with the coach.
You mention your son is not a "star" but works hard. Is he a starter? You'll find out quickly in the college world (Juco, NCAA, NAIA) regardless of level all college athletes were studs at the high school level. Even at the JuCo level. If he's got potential (projectable) he may do well. Has he participated in any showcases? Have you had his skills evaluated by a independent third party? Even at the JuCo DIII level, coaches prefer/want a minimum skill set. This ain't Little League anymore.
HS Athletes that have been recruited for college usually get "helped" through the process whereas a walk-on is with the masses. The coach was instrumental in pairing our son up with another recruited player regarding housing. When it came time to register for classes, the coach walked him through the process. He had also mailed us a packet with a lot of information regarding housing, school registration, team meetings, etc. A lot of this took place fairly quickly as he didn't commit until late in his senior year and we had only a month or two to find housing, pay deposits, move his stuff and then get him registered for classes, buy/rent books and get him settled in.
Where in NY are you located? I'm a former NY resident from the southern Tier area (Binghamton).