Greece Teachers' Guide
People have been studying the Greeks for so long that we have learned to see them in many different ways. Some people see the Greeks as the beginning of Western Civilization: if you want to take this approach, you might teach about how the Greeks invented the geometrical proof, and the scientific method, and the writing of history, and plays, and you might mention how much our literature owes to Greek mythology and our civic architecture owes to the Greek temple and how much our churches owe to the Greek basilica, and our theaters to the Greek theater.
Other people are more interested in showing how much the Greeks themselves learned from other, older cultures. If you took this approach, you might show how the Greeks learned sculpture from the Egyptians, and the alphabet from the Phoenicians, and pottery and farming and astronomy from the Sumerians, and iron and horse-rearing from the Hittites, and coinage from the Lydians.
Other people see the Greeks as very different from us; then they'd talk about Greek animal (and sometimes human) sacrifice, the isolation and powerlessness of Greek women, and the importance of slavery in the Greek world. They might talk about the importance to the Greeks of the agon between nomos and physis.
I think the most interesting approach is to show all of these things: the Greeks were different from us in some ways, and like us in others. We learned some things from the Greeks, and they learned some things from other people. Let the children themselves decide which things are like us and which things are different, and which things they would want to imitate and which things they would not.