I'd make a written set of talking points-- an outline of how YOU would prefer the meeting to go, in terms of what MUST be addressed, and what you'd LIKE to have addressed.
Then go back through it, placing yourself in the position of the classroom teacher, and edit anything that seems inflammatory in any way, shape or form.
Stick to factual statements-- or at least very bland/uncharged language in subjective statements. Use third-person narrative statements wherever possible, as those are less threatening/emotionally charged than I/you/they statements are.
Write your talking points as though you were writing them for a friend's child rather than your own, if you can.
Go into your meeting while holding on to your attitude that this MUST just be a misunderstanding... because
of course the school wants to help your child. (And really-- while opinions may vary on the details, that much probably IS actually true... if you find yourself becoming emotional during the meeting, focus on taking notes for a minute and remind yourself of that fact.)
You're the expert on your child, they are the experts on their school. Your child needs both to be brought to bear on the situation if he is to succeed.
Good luck!
