OIL or CANDLES? The candles to be used in Hanuka could be made of wax, paraffin, etc. but ideally one should use olive oil candles, because the miracle of Hanuka happened with olive oil. Moreover, oil candles will usually last for a longer time than regular or small wax candles. The Mitsva of Hanuka candles cannot be performed with 'electrical candles', even when real candles are not available. An electrical Hanukia, however, can be placed in the house or in the Synagogue in addition to the regular Hanukia, especially during day-time.
WHERE? Ideally the Hanukia should be placed outside the house's main entrance door, on the opposite side of the Mezuza. Nowadays, however, most families place the Hanuka candles inside the house. Since part of this Mitsva is pirsume nisa (to publicize the miracle performed to our ancestors) when lighting the candles inside the house we should place the Hanukia behind a window, in a spot visible from outside.
HOW MANY CANDLES? Technically, it is enough to light one single candle (and the shamash or accessory candle) each night of Hanuka. The traditional custom anyways is to add one extra candle each night. However, in some cases where one cannot light additional candles, for example, if one is on a trip or in a Hotel room, etc., lighting one candle any night will be enough.
A FAMILY MITSVA: Unlike most Mitsvot (=Jewish religious commandments), Hanuka is not an individual Mitsva like Tefila or Tsedaqa, but a family Mitsva. In some ways it is similar (but not identical) to the Mitsva of lighting Shabbat candles, which is not a requirement for each individual but for the family as a whole. Following, I will present some illustrations that will help us understand the practical aspect of this particularity.
1. If one's son or daughter lives overseas, and she is financially dependent on her parents, she does not need to light her own Hanuka candles. To this effect, a son or daughter are considered part of the family while they are financially dependent on their parents (somekh al shulhan abiv). However, if a son, even an unmarried son, lives on his own house and he is financially independent from his parents he should light his own candles with Berakha, etc.
2. If the husband is in a business trip, he is technically included in the candle lighting done at home by his wife and children. In other words, he does not have to light his own individual Hanukia in his hotel room. However, if he still wants to light the candles in his room, he could do it, but without saying a Berakha.