Zambians still follow a lot of cultural norms that respect social hierarchies.
Older men and women are afforded more respect than younger men and women. You might find, however, that a white person may be afforded cultural norms and behave however he/she pleases. A holdover from colonial times, this might make a traveler uncomfortable, but this is largely a Zambiansí way of being friendly to foreigners. Accept their hospitality.
When meeting a Zambian, even just to ask a question, you should always say hello and ask how they are. Properly greeting a Zambian is very important. They are uncomfortable with the Western notion of simply "getting to the point."
Zambians love to shake hands, and you should oblige them. However, Zambians sometimes like to hold hands for the duration of a conversation. This should not be interpreted as anything sexual; they are merely trying to "connect" with you. If you feel uncomfortable, simply say that is uncomfortable where you come from.
Women should not wear shorts or mini-skirts, especially as they travel away from Lusaka.
A present will be appreciated, but not necessarily expected - something from your country, or something from town unlikely to be easily obtained in a village (e.g. bread, sugar or tea). You may be offered a present when you leave (e.g. a chicken). Donít refuse it.