I don't know if this is the kind of advice you're asking for, but it's the best I've got to give...

Be aware that the SB5 is a very loooong test! Make sure he knows he can (and should) take breaks when he needs them.

My DS6 was utterly tuckered out after the SB5. In fact, when he took the WISC, at the end he said, "That's all? We're done already?"

Big difference!

Kriston