My gosh, I am ashamed I didn't think of this first. By all means, have the Sheraton help you find a tour of the Cape Flats, District Six, and be sure to go to Robben Island. It would be a real shame to go to South Africa and come away with no sense of the history of the struggle, and how it is currently playing out. Please, please do this. It is a day well worth spending.
Also, as to reading, almost anything by Nadine Gordimer (JULY'S PEOPLE or HOUSE GUN)or J.M. Coetzee (especially DISGRACE) would be good airplane reading.