The basic elements of a kosher menorah are eight holders for oil or candles and an additional holder, set apart from the rest, for the shamash ("attendant") candle.
The Chanukah lights can either be candle flames or oil-fueled. Since the miracle of Chanukah happened with olive oil – the little cruse of oil that lasted for eight days – an oil menorah is preferable to a candle one, and olive oil is the ideal fuel. Cotton wicks are preferred because of the smooth flame they produce.
Whenever purchasing a mitzvah article, we try to buy the most beautiful one that is within our means. So, if at all possible, go for the silver menorah. Beautifying a mitzvah is our way of expressing our appreciation to G‑d, and showing how dearly we hold His commandments.
The eight candles of the menorah must be arranged in a straight, even line, not in a zigzag or with some lights higher than others. If it is an oil menorah, the oil cups must hold enough oil to burn for the required time – at least 30 minutes on weeknights, and up to one-and-a-half hours on Friday evening (see Special Shabbat Rules). If it is a candle menorah, the candles should be large enough to burn for the required time.
Electric menorahs are great for display purposes, and are a wonderful medium for publicizing the Chanukah miracle. But the Chanukah lights used to fulfill the mitzvah should be real flames fueled by wax or oil – like the flames in the Holy Temple.