You've already received great advice above, all of which I second. Like goofs, I haven't been to a school meeting for this specific reason, but I've been to quite a few school meetings for other issues
The things I'd add - the school has invited the staff they feel they can rely on for input and insight. You are also able to invite other people if you think they have something to add to help the team work come up with solutions or understand your ds better. If you think his private psych has any insight or could help with problem-solving, you could invite the psych (you'd have to pay to invite the psych, so another less expensive option is to simply talk to the psych in advance of the meeting, and ask for his/her input).
I would also talk to your ds and see what he feels the issue is, as well as ask him what solutions he'd suggest.
I find it's really helpful to first prepare prepare prepare as much as you can - anticipate questions from the school and figure out how you'll answer them as much as you can. Then go in and *listen*. Prepare for issues up front, but don't go in expecting them. Hope that makes sense!
Best wishes,
polarbear
