The Shamash-Purpose & Halachic details-Part 2
E. How long is the Shamash to last for?
The Shamash is to last for at least 30 minutes after nightfall.
F. When to light the Shamash:
The candle which is used to light all the other candles is to be lit before the start of the blessing in order not to make an interval between the blessing and the lighting. [This comes to negate those who first say the blessing and then strike the match to light the Shamash, hence making an unnecessary interval between the blessing and lighting of the Chanukah lights.] Those who are accustomed to light an additional oil candle as the Shamash, are to light this candle only after all the other candles of that day are lit.
G. Who should light the Shamash?
Any person, even a child, may be delegated the duty of lighting the Shamash, which also is a slight Mitzvah.
H. Its position by the Menorah:
At a distance: The Shamash is to be placed at a recognizable distance from the rest of the candles.
Higher up: The Shamash is to be placed higher than the other Chanukah candles. This can be accomplished either by having a Shamash that is longer than the rest of the candles, or by placing the Shamash on a higher plane than the rest of the candles.
Right or left, and front or back: The Shamash may be positioned as one wishes whether to the right or to the left of the Menorah, or in back or in front of the Menorah.
I. Benefiting from the Shamash:
It is permitted to receive benefit from the Shamash that is positioned near the Chanukah candles. One may light other candles from it and may use its light for benefit. Nevertheless, initially, one is not to benefit from the Shamash if it is together with the other candles and not individually recognizable from them. Likewise, initially, one may not use the light of the joint candles even when the Shamash is lit unless it is clear that one is only using the light of the Shamash.
J. May one extinguish the Shamash once it has been lit for a half hour:
After the passing of a half hour past nightfall, the Shamash may be extinguished. This applies according to all opinions, even if one did not perform a stipulation over it prior to lighting. [If one is using a different candle for the Shamash then the candle that was used to light all the other candles, Shamash included, then this candle that has been used to light all the candles may be extinguished may be extinguished as soon as one finishes lighting all the candles, including the Shamash.]
K. When many people are lighting in the same home, is each one to have their own Shamash?
Being that every person is to light the candles in their own individual area, therefore each individual needs to have their own Shamash. [However, if for whatever reason they are lighting near each other, then technically, a Shamash is not required for each one. Nevertheless, the custom is for each individual to have their own Shamash, as it contains mystical meaning.]
L. Should a Shamash be lit also when lighting the Menorah in Shul during the day:
M. Using the flame of the Chanukah candles to light the Shamash:
It is forbidden to light any mundane candle from an already lit Chanukah candle. This prohibition applies even against lighting a candle that will be used to light the other Chanukah candles. [Hence, one may not light the Shamash from a Chanukah candle.] However, some Poskim rule one may light a mundane candle [i.e. the Shamash] for the sake of lighting other Chanukah candles, so long as there is no concern that it will extinguish prior to having a chance to light the Chanukah candles. Practically, we are stringent in this matter.
 See Nitei Gavriel 20
 See Kinyan Torah 2:102
 Nitei Gavriel 23:11; See Michaber 206:3; Admur 167:3; However, see Admur Seder 9:2, Luach 6:2, and 206:3 that one is to not cut a fruit until after the blessing, as it is a Mitzvah Min Hamuvchar to say the blessing on a whole food and that this is not considered a Hefsek, as it is done for the sake of the eating.
 Ben Ish Chaiy Vayeishev 18; Kaf Hachaim 671:83
 Michaber 673:1; Rabbeinu Yerucham
 Rama ibid “The Shamash should be longer than the other candles so if one comes to use the light of the Menorah one will use its light”; Mordechai; Sefer Haminhagim p. 159
 The reason: This is done in order so if one come to make use of the candles, then he will make use of the Shamash which is higher up. [Rama ibid]
 Rama ibid
 M”A 673:7; Bach end of 673; Maharil Chanukah p. 403; Maglei Tzedek Chanukah 18a; M”B 673:20
 See Nitei Gavriel 20:2-3 that he was witnessed all customs
 Elya Raba 673:10; Shaareiy Teshuvah 673; M”B 673:15; Biur Halacha 673:1 “Sheim Yishtamesh” in name of Machatzis Hashekel
Other opinions: Some Poskim rule it is initially forbidden to benefit from the light of the Shamash, even if the Shamash is individually recognizable from the other candles. [P”M 673 A”A 4 in explanation of M”A 673:4; P”M 673 A”A 1; See Piskeiy Teshuvos 673:7]
 M”A 673:4; M”B ibid
 M”B 673:15 in name of M”A
 Yosef Ometz 1076; Kinyan Torah 2:102; Shraga Hameir 3:16; Piskeiy Teshuvos 672:5
 M”A 673:5; Elya Raba 673:10; M”B 673:18
 Rama 671:2 and 671:7
The reason: This is done in order so it be recognizable the amount of candles being lit that night. [ibid] By doing so, one satisfies even the opinion of Tosafus. [Biur Halacha 671:2 “Veyizharu”] However, when each Menorah is not individually recognizable, people can mistake the number of candles being lit that night, having joined the candles lit on two different Menorahs.
 See Kav Hayashar 96; Piskeiy Teshuvos 673:7
 Melamed Lehoil 121; Orchos Chaim 671:13
The reason: Some say the reason for this custom is to fulfill one’s obligation according to the Rambam who ruled that also by day the Menorah was lit. [Orchos Chaim 671:13]
 Likkutei Sichos 18:315 [printed in Shulchan Menachem 3:270]
 Michaber 674:1; Shabbos 22a
 Michaber ibid; Rosh in name of Rif; Ramban; Rav in Shabbos ibid
The reason: As it appears as a belittlement to the Mitzvah, as not everyone is aware that one plans to light the Chanukah candle with it. [Levush; Taz 674:1]
 M”B 674:3 in name of Peri Chadash and so is implied from the Michaber ibid; Kaf Hachaim 674:7
 2nd opinion in Michaber ibid; Sefer Haterumos; Ran; Shmuel in Shabbos ibid
 Rama ibid; Kaf Hachaim 674:8 that this applies even according to the Sefaradim