I have summarized information from the Joburg.org.za website and from ticketbreak.co.za website. Tickets to the Park and Rides/Walks can be booked at ticketbreak.co.za 

IF you do not have your own car you will need to use DROP AND RIDE
A Drop & Ride will be provided at Westgate where fans can be dropped off by family/friends/organized taxi.  The Westgate Transport Hub is near the Mary Fitzgerald Square Cnr Anderson Street and Miriam Makeba St/Pat Mbatha Bus & Taxiway, south of Newtown, CBD (closest highway: M2, off ramp Selby).  It has a Rea Vaya serving Ellis Park and Soccer City Stadiums. Rea Vaya is the city’s brand new bus rapid transport [BRT] system which runs west east from Soweto, through Central Johannesburg to Ellis Park. Price R12 return Tickets can be bought from all Rea Vaya Stations. Metrorail which is the City’s commuter train service will also link to Westgate but it is unlikely that international fans will be making heavy use of Metrorail.]

If you have a car:  Either PARK AND RIDE or PARK AND WALK
The City of Johannesburg has provided secure and affordable Park & Rides and Park & Walks. In order to access Park & Rides and Park & Walks you have to buy a transport ticket to book a parking space for your vehicle. This will ease congestion and allow you to rest assured that you will be able to get to your game safely and on time.
Park and Rides allow you to park your car close to the stadiums and be transported safely via shuttle and back. Prepaid ticket PRICE from R50 per car
Park and Walks allow you to park your car close to the stadiums and walk safely along a designated route to the stadium and back. Prepaid ticket PRICE from R50 per car
PLEASE NOTE:  There will be no access to Park & Rides and Park & Walks sites on game days without a ticket. You will need to purchase 1 Transport ticket per vehicle not per person. There will be no Drop and Ride (drop-off areas) at the Park & Ride or Park & Walks. The ticket price at Park and Ride Sites, includes your parking vehicle fee and the tansport fare to the stadium.   All Park and Ride and Park and Walks will operate from 4 hours before kick-off to 4.
Where are the Park and Rides/Park and Walks?
Ellis Park
Park & Ride
• Bez Valley: Marcia Street, Observatory (east of CBD)
• Wits Campus: Enoch Sontonga Avenue, Braamfontein (northwest CBD)
• Con Hill (Constitution Hill): 92 Joubert Street, Braampark (northeast of CBD)
Ellis Park & Walk  Athlone Boys: 70 Bezuidenhout Ave, Cnr 3rd & 4th Str, Bezuidenhout Valley (1.8km to the stadium)
Soccer City Park & Ride  * Wits: Cnr Enoch Sontonga Avenue & Empire Road, Braamfontein (northwest CBD)
*  Gold Reef: Data Crescent, Gold Reef (south of CBD)
Soccer City Park and Walk
*Aeroton: Adcock Ingram Ave, Aeroton (approx 2km to the stadium)
*Shareworld: Nasrec Rd, Nasrec (900m to the stadium)
*Rand Show Road: Cnr Randshow & Aerodome Rd, Aeroton (approx 2km to the stadium)

Sandton Transport Hub    At different places in the Sandton area there will be pick up and drop off points for Metrobus, Gautrain and Buses from Lanseria Airport. Sandton Metrobus Service is a bus service from the Sandton Transport Hub to Westgate Transport Hub on match days. PRICE R20 one way to Westgate, R40 return to Westgate and R50 return ( including your Rea Vaya connection to the stadium)  
What airport services are available?
From OR Tambo International Airport [ORT]:
  Gautrain rapid rail system operates to Sandton, via Rhodesfield and Marlboro Stations, with feeder buses from Sandton Station servicing Rivonia, Rosebank and the CBD. From Sandton to get to your game you can catch the Metrobus Service to Westgate, thereafter use Rea Vaya BRT or Metrorail to get you to the stadium. On match days there will be buses to the Westgate Transport Hub directly.
From Lanseria Airport:  Catch a shuttle to the Sandton Transport Hub and on game days use the Metrobus Service to Westgate; thereafter use Rea Vaya BRT or Metrorail to get you to the stadium
Where do I buy my transport tickets from?
www.ticketbreak.co.za  will be selling tickets online from the 14 May.