College program spots, as far as I know, AREN'T competitive. You walk in, have SAT scores that are good enough(1300+ would be my guess) then say you want in. There's practically no competition for them whatsoever. I mean, you're not even going to get reimbursed in any way. It just sets you up better to pick up a scholarship later, and/or if you're wishy-washy on whether or not you want to commit, it gives you a little more time to think on it. College Program also works for ppl who got rejected form scholarship but still want to join. Odds are quite a few people will drop from the unit you join...meaning if you're still around after 1 or two years, and you prove you have your **** together, they'll give it to you.
As for contacting, I'd do it the academic year before. The "recruiter" is probably the unit's freshman adviser(an LT) at the school you plan to go to. As a result, during summer cruise, they be busy.
Also, that way you can ask if there's an orientation before the school year starts, which would be beneficial for you. It's kind of awkward entering a class full of guy's who've gone through O-week when you haven't.