Michael,
Etosha is one of the truly great Game Parks, although it is far from exclusive.
I presume you will be staying inside the park at Okaukuejo, Halali and Namutoni
We always get up early get out of the gate as soon as you are allowed (sunrise), and stay out all day, parking up at any of the waterholes when it gets hot, do not forget plenty of water.
The possibilities are endless but I would suggest a daily trip around the waterholes in your area.
There should be plenty of plains game including relative rarities such as Black-Faced Impalla.
If you do not see Lion I will be very surprised, chances for Cheetah and Leopard are quite remote, we have only seen 2 Cheetah and 1 Leopard in 6 visits. Birding is not stupendous, but you will certainly see lots of Pale Chanting Goshawk, Kori Bustards and Korhaans.
At Okaukuejo you have what is in my opinion the greatest waterhole in the world, you may have some late nights.
Have a great trip, if you need more detailed information please send me a PM.