Justlanded: South Africa offers resources and background on living in visas, working, living, and moving to the country.
Numbeo: Cost of Living in South Africa is a fine crowdsourced site that provides information about the cost of living in South Africa that should help prepare you for the transition.
Lonely Planet: Complete Guide to South Africa makes it easy for travelers to deal with the daily challenges independent travelers face: how to get around, where to stay, where to eat, and much more.
Rough Guides: Travel Guide South Africa describes various attractions and destinations, while also providing practical travel tips about transportation, safety, and other travel essentials.