Namibia is perfect for an adventurous driving holiday. There are plenty of companies that will rent you a truck with tents and camping gear. Most of the gravel roads are maintained pretty well. If you want to go onto the 4×4 tracks, it helps to know your way around four wheel drive (to some extent) and if you are planning to drive in deep sand, take plenty of advice about tyre pressures and techniques. There is lots of good advice to be had on the various Internet forums – Tripadvisor forums are a good source.
There are incredible sights to see and lots of good places to stay: campsites and lodges. Book them in advance in the holiday periods, particularly in Etosha. The remote areas should be taken seriously though. Some of the routes through Kaokoland are extremely tough going and a breakdown of any sort could see you stranded for days. There is no cell coverage there so take a satphone if you are on your own. Plan your routes carefully and don’t leave it until the last minute to get fuel – the next pumps could be many hours away. Be aware that what doesn’t seem that far on the map could be a lot slower if the gravel road is badly corrugated, or barely there at all. Don’t drive at night if you can possibly avoid it; you can’t see the road surface clearly or the animals getting ready to spring out in front of you. The advice we were given in Opuwo (and took) was that it’s better to try to camp near other people if you can’t reach your destination, and get their permission first.