Here is a short history of South Africa from Wikipedia: History of South Africa:
Following the defeat of the Boers in the Anglo-Boer or South African War (1899–1902), the Union of South Africa was created as a self-governing dominion of the British Empire on 31 May 1910 in terms of the South Africa Act 1909, which amalgamated the four previously separate British colonies: Cape Colony, Colony of Natal, Transvaal Colony, and Orange River Colony. The country became a fully sovereign nation state within the British Empire, in 1934 following enactment of the Status of the Union Act. The monarchy came to an end on 31 May 1961, replaced by a republic as the consequence of a 1960 referendum, which legitimized the country becoming the Republic of South Africa.Settlement of the Cape of Good Hope at the southern tip of the African continent began with a Dutch East India Company trading post in 1652. The British invaded the Cape in 1785 and the Dutch settlers moved inland in what is known as the Great Trek and established Boer settlements in the interior. The population of the entire area including the present countries is a mixture of the original African population, Portuguese, Dutch, French, German, and British immigrants and enslaved people imported from the north of Africa and from the Dutch Colonies in Asia. South Africa also has the largest population of immigrants from India on the African continent. Obviously, the history of South Africa and the surrounding countries is much more complicated than this short summary. To do adequate genealogy, you will need to start with understanding the history of the countries where your ancestors lived as well as the countries from which they immigrated.
Two good places to start your research are the short summary of sources in Rosemary Dixon-Smith's website page entitled, "A Research Guide for Beginners" and the South African Genealogy Page. A more complete list of sources is available from the South Africa pages of The Family History Guide. Each of the major genealogical websites has a collection of records linked from The Family History Guide page. Another good place to start is with the FamilySearch.org Research Wiki page for South Africa Genealogy. You will need to remember to look for records in the country of origin of your ancestors and also remember the time periods when South Africa was under the control of the different European nations. For example, records of British South Africa may be located in Great Britain.
Once you begin to realize that genealogical records all fall into the same categories, you will find it much easier to do research in different countries. The initial orientation should always include the history but it is also important to begin with a survey of the types of records that are reasonably available and the records' location.
Here is a list of useful books about South African Genealogy and History.
Dutch Reformed Church Archives (Stellenbosch, South Africa). South Africa, Cape Province, Beaconsfield, Church Records. Salt Lake City, Utah: Digital capture by the Genealogical Society of Utah, 2007.
———. South Africa, Transvaal, Krugersdorp, Church Records. Salt Lake City, Utah: Digital capture by the Genealogical Society of Utah, 2007.
———. South Africa, Transvaal, Mara, Church Records. Salt Lake City, Utah: Digital capture by the Genealogical Society of Utah, 2007.
Finkelman, Paul. Encyclopedia of African American History, 1896 to the Present: From the Age of Segregation to the Twenty-First Century. New York: Oxford University Press, 2009.
Genealogical Society of South Africa. An Abridged Guide to Genealogical Research in South Africa. Houghton [Johannesburg: Genealogical Society of South Africa (PO Box 2119, Houghton, Johannesburg 2041), 1995.
Genealogical Society of South Africa, South Africa, Directorate State Archives and Heraldic Services, and National Archives of South Africa. Alphabetical Guide to Gravestones in Smaller Cemeteries in South Africa. Pretoria? State Archives Service, 1989.
Genealogical Society of South Africa, and Southern Transvaal Branch. Intermediate Guide to Genealogical Research in South Africa. Saxonwold, South Africa: Southern Transvaal Branch of the Genealogical Society of South Africa, 1996.
Genealogical Society of South Africa, and State Archives Service (South Africa). Alphabetical Guide to Gravestones in Smaller Cemeteries in South Africa. Pretoria: State Archives Service, 1988.
Malan, Hercules M. Guide to the Malans of South Africa, History and Genealogy. Place of publication not identified: publisher not identified, 1998.
Natal Inland Family History Society, Genealogical Society of South Africa, and Natal Midlands Branch. “GNUS: The Quarterly Newsletter of the Natal Inland Family History Society and Natal Midlands Branch of the Genealogical Society of South Africa.” GNUS : The Quarterly Newsletter of the Natal Inland Family History Society and Natal Midlands Branch of the Genealogical Society of South Africa.
Pama, C. Genealogy in South Africa. S.pl.
Reaman, George Elmore. The Trail of the Huguenots in Europe, the United States, South Africa, and Canada. Baltimore: Genealogical Pub. Co., 2000.
South Africa, and Department of Justice and Constitutional Development. South Africa, Eastern Cape, Estate Files,. Salt Lake City, Utah: Digital capture by the Genealogical Society of Utah, 2013.