well since he asked about Zaino in particular, we are assuming that is what he is looking for advice on. There are other 90 step threads on how to wash a car or "what is the best wax to use?"
Here is a neat article where a guy tested Zaino VS some other products on an NSX hood:
http://www.ffcobra.com/magazine/waxtest.html
Here is a pic of a quick detail JamesGott did on my car recently. Rinse, clay bar, one coat each of z5, z2. Sure it could use more, as I daily drive it but pretty darn good for 1 quick coat of each and big improvement.
For local Atlanta people, James does an outstanding job detailing and his prices can't be beat. You supply the Zaino, he'll do this for you inside and out, wheels and all for $100. Leave him a good tip. He can even come to you if need be.