I was lucky enough to spend a few days in Kruger Park in June 2009. It was before I acquired my digital SLR so these were taken with a Fuji Finepix S5000
It was a fantastic experience and if you get to South Africa and have the time to go the park, it is the experience of a lifetime.
The Sat Nav co-ordinates to the Protea Hotel, KRuger Gate, where I stayed, are -24.977587, 31.479531.
It is well worth taking a tour for the first couple of visits, and then think about taking your car. However, the tour leaves you free to focus on enjoying yourself.
I was there in June and there was plenty to see. It was freezing cold early in the morning and yet quite warm during the day.
Well worth it, trip of a lifetime.