Visa RequirementsMost nationalities don't need a visa to enter South Africa as a tourist as long as your stay doesn't exceed 30-90 days. You need a valid passport that doesn't expire within 6 months and with at least one empty page for endorsements. For a list of visa requirements per nationality see the South Africa Department of Home Affairs site.
HealthSouth Africa has some of the best doctors and hospitals in the world. As I learned at school, the very first heart transplant was performed in Cape Town. So if you need to be hospitalized you're in good hands. Make sure you get travel insurance since quality healthcare is not cheap.
You can drink the tap water throughout the country (it's safe even if it looks a little brown coming out of the tap in some areas). Drinking water straight from rivers however can put you at risk for bilharzia. More health information follows below.
No vaccinations are required by law to enter South Africa. If you are traveling from a country where Yellow Fever is present you will need to prove you have had the inoculation by presenting a valid international yellow fever inoculation certificate. Both Typhoid and Hepatitis A vaccinations are highly recommended. Get up to date with your measles vaccine too, there have been recent outbreaks in Cape Town and a few other areas in the country.
Most of the main tourist destinations in South Africa are malaria free, making South Africa a particularly good destination to travel to with kids. The only areas where malaria is still prevalent are the Lowveld of Mpumalanga and Limpopo and on the Maputaland coast of KwaZulu-Natal, see this map to find out exactly where that is. It does include the Kruger National Park.
Make sure your doctor or travel clinic knows you are traveling to South Africa (don't just say Africa) so s/he can prescribe the right anti-malarial medication. Tips on how to avoid malaria will also help.
South Africa has one of the highest rates of HIV in the world so please take precautions if you are planning to have sex.
Although there is a high crime rate in South Africa it is mostly restricted to the townships and not tourist areas. You should be careful when changing large amounts of money, make copies of your passport and keep them in your luggage and just be careful about walking around at night especially in the major cities. More safety tips...
The roads in South Africa are among the best in Africa which makes it a good place to rent a car and do some independent sightseeing. Try to avoid driving at night since the roads aren't well lit and animals tend to venture on to them at will. Take care when driving on the approaching roads to Kruger National Park, there have been reports of carjackings, although the police are aware and have increased their vigilance.
CurrencyThe South African unit of currency is called the Rand and it is divided in to 100 cents. Coins come in denominations of 1c, 2c, 5c, 10c, 20c, 50c, R1, R2 and R5, and notes in denominations of R10, R20, R50, R100 and R200. Due to favorable exchange rates, South Africa is a very inexpensive destination given the quality of lodging, dining and activities offered. Check here for current exchange rate information. Credit Cards are widely accepted (except at gas stations)and ATM machines are widely available in the main cities and towns.
It is normal to tip in South Africa, so keep your small change handy. In restaurants 10-15% is standard. Tipping tour guides, trackers and and game rangers is also the norm since they depend on this for most of their income.
Bartering and exchanging jeans and sneakers (especially name brands) for arts and crafts is common practice. Bring a few extras along with you.