Applying for a visa can be administratively daunting, especially of it's your first time.
When make an application for a US Visa there are few things you need to keep in mind as well.
South Africans applying for a US visa can do so at any of the three U.S. Consulates in Johannesburg, Cape Town, and Durban.
The earlier the better
Don't waste time starting the application process. Earlier this month the consulate had a notice on it's website that encouraged South Africans seeking to apply for visa's to do so timeously. The statement reads: "the U.S. Mission aims to keep the wait time for appointments at a minimum. However, heavy demand for U.S. visas has currently led to a longer than usual wait time in South Africa."
Check out this story and link Six sure ways to get your visa application denied it's a great resource to keep on file.
VisaUSANow is also one of the most useful blogs out there with great hints and the latest news on visa applications. There are practical guides as well as topics such as Can I get married with a tourist visa just in case you ever needed to know.
Keep in mind that the US State Department recently changed it's regulations and now requires people to submit social media profiles and five years worth of email addresses.
This is just one reason why you need to keep updated with the ever changing requirements for US Visa applications.