Hello,
Nothing really special. South Africa is a good start. <img src="/images/graemlins/grin.gif" alt="" />
Have water (bottled) always with you, some change for tips, maybe a cellphone (though coverage is only for the cities-highways-northern part-river, he hopefully will not leave the beaten track) and always obey the "not recommended for tourists" advices. Without judging your brother, it is not wise to show off (like wearing expensive things, etc.) in certain parts of Cairo. (I can't really recall that exactly, it was long years ago, but I think it's still the case.)
But generally: he should not leave the group and he will be fine. Egypt is a beautiful country, he'll love it.