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 much aggregate and itemized information about the cost of living in the country, the main cities, and bigger towns which 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.