Driving in Namibia
Driving yourself around Namibia is, for most visitors, by far the best way to see the country. It is much easier than driving around Europe or the USA: the roads are excellent, the traffic is light, and the signposts are numerous, clear and unambiguous.
Further, if you choose to visit private camps or concession areas, you can then use the skills of the resident guides to show you the wildlife. You're not restricted to the car, to be in it every day. Driving yourself gives you freedom to explore and to go where you like, when you like.
It's generally easiest to hire a vehicle for your whole time in Namibia, collecting it at the airport when you arrive, and returning it there when you depart. This also removes any worries that you may have about bringing too much luggage (whatever you bring is simply thrown in the boot on arrival).
However, if your budget is very tight then you may think about just taking a vehicle for a few days, perhaps from Windhoek to Swakopmund via the Sesriem area, or to drive around Etosha. However long you keep the vehicle, the type you choose and the company you hire from can make an enormous difference to your trip.