Proverbs are similiar to Idioms, but they are complete sentences that are often used in conversation. The meaning behind them is often culturally based.

People who live in glass houses shouldn't throw stones -

A penny saved is a penny earned (attributed to Ben Franklin) -

Don't look a gift horse in the mouth -

Beware of greeks bearing gifts (gifts bearing greeks?) - A reference to the Trojan Horse, a secret military plan devised by Odysseus (Ulysseus), where the Greek army pretended to give up on their siege of Troy and sail away, leaving behind a great wooden horse. The Trojans assumed this was a gift from the greeks and brought it inside their heavily fortified city walls. During the night, greek soldiers climbed out of the horse and opened the gate to allow the rest of their army to enter the city and burn it to the ground.

The apple doesn't fall far from the tree -