JoAnna,
You might also tell him that they have some security protocols because some of the adults there are taking high stakes tests. Thus, he may be asked to show that his pockets are empty, turn around and show he doesn't have electronics hidden on his person, and we saw them make one woman with a large locket remove it! The people at the center were very nice to my son, but it still freaked him out a little bit the first time he went (he tested last year as a 2nd grader and this year again).
Also, make sure he understands about the break, and watch the time when you take the break.
My son came out the first time (in a much what I worried was a much too short amount of time) grinning and saying it was fun!
And yes, scores are available online really quickly.
