One of the great things about sitting at a waterhole and watching the aninals is the chance to enjoy the behaviour and interaction between them, its is also the best place for photos as it give you the chance to position yoursef and get all your camera equipment ready as you wait for the action to arrive!
Remember as you drive around that they are all wild animals, so remain in your vehicle at all times and stay on the roads. Elephant and Rhino are more than capable of tipping your vehicle over ifm you upset them.....!
A visit to Etosha will provide you a memorable experience that you will never forget, very few places in the world can offer such a dramatic wildlife experience and Namibia is such a stunning country and very easy to travel around, so add it to your list of must visit places, and when you are there send me a picture so I can be jealous!