My understanding is that the talent search agencies don't recommend studying beyond becoming familiar with the format of the test. We didn't do anything to prep dd#1 when she took it in 4th grade other than doing the practice questions they sent. She's taking the SAT this year and hasn't so much as looked at the practice booklet b/c she has totally overscheduled herself with extracurricular activities and is rarely home and awake to look over practice exams.
My biggest advice would be to tell him that is is probably going to be harder than the practice questions and that he shouldn't expect to know all or even most of the questions. Dd was so thrown by it being harder than she expected that she kept leaving the room to go to the bathroom and cry. She didn't complete the reading section at all, which is usually her strongest area, and she came out in tears at the end. She did much better than I had expected based upon how stressed she was, but less anxiety would have been a good thing.
My oldest is doing much better with stress in relation to hard tests now a days and I do think that it was a good learning experience, though.
