In 2002 i made a tour through Namibia before going to South Africa for the solar eclipse.
It was perfect, the tour organization was crazykudu in Windhoek.
After that i drove around by rented car. Below is a clickable map of Namibia (borrowed from crazy kudu).
The brown line shows the road the tour went. The blue line is the road i took myself. Click here for the first photo.
Good book about Namibia is "Solitaire" by van der Lee (probably only in dutch).