The Blessing: One first lights the candles and then says the blessing of “Baruch Ata Hashem Elokeinu Melech Haolam Asher Kidishanu Bimitzvosav Vetzivanu Lehadlik Neir Shel Yom Hazikaron”. This blessing is then followed by the blessing of Shehechiyanu. [Regarding saying this blessing of Shehechiyanu on the second night-see the next section Chapter 2 Halacha 11] When Erev Rosh Hashanah falls on Erev Shabbos one recites “Baruch Ata Hashem Elokeinu Melech Haolam Asher Kidishanu Bimitzvosav Vetzivanu Lehadlik Neir Shel Shabbos Vishel Yom Hazikaron” and then Shehechiyanu.
When are the candles lit? The custom is to light the candles prior to sunset at the same time that they are lit on Erev Shabbos. [One who did not light the candles prior to sunset is to light the candles at night, on Yom Tov, from a Preexisting flame. It is to be lit at the very least prior to the return of the men from Shul.]
If a man is lighting candles when is he to say the blessing of Shehechiyanu, by lighting or by Kiddush?
A man always says the blessing of Shehechiyanu by Kiddush, even in the event that he is lighting candles. However in such a case he is to light candles directly before Kiddush, hence having the blessing of Shehechiyanu also go on the candle lighting. If however he said the blessing by candle lighting he does not repeat the blessing by Kiddush.
Does a woman who will be saying Kiddush say Shehechiyanu by candle lighting or by Kiddush?
She is to say the blessing by candle lighting.
If a man is lighting candles does he first light the candles and then say the blessing or vice versa?
Some Poskim rule men are to follow the same order as women and hence first light the candles and then say the blessing. Other Poskim however rule that men are to always first say the blessing and then light. [See footnote for opinion of Admur]
Preparing a 24 hour candle:
It is proper to prepare a 24 hour candle on Erev Rosh Hashanah in order to have a preexisting flame available to use on Yom Tov.
Those that have a Yartzite on Rosh Hashanah are to light the Yartzite candle before Yom Tov. One who did not do so before Yom Tov may light it on Yom Tov inside an active Shul by the room where the prayer takes place. However one may not light the candle in one’s home on Yom Tov. However there are opinions which allow lighting it even at home.
In the event that Rosh Hashanah falls on Thursday and Erev Shabbos, those that are accustomed to light the Teshuvah candle are preferably to do so from before Yom Tov. However some write that it is permitted to do so even on Yom Tov.
The reason: This applies even on Yom Tov despite that on Yom Tov extending a flame is permitted, as the Sages did not wish to differentiate between the lightings of Shabbos and Yom Tov. [ibid]
At night: This ruling applies even if one is lighting the candles at night. [Hiskashrus]
Other Opinions: Some Poskim rule that on Erev Yom Tov one is to first recite the blessing and then light the candles. [Mateh Efraim 625/33] Some rule that this especially applies when one is lighting the candles at night as at that time no one would mistakenly think one can also do so on Shabbos. [Mateh Efraim ibid; Alef Lamateh 625/50]
 Sefer Haminhagim p.117 [English]; Likkutei Sichos 14/378; Igros Kodesh 6/125; 3/140; Shulchan Menachem 3/84; See Shaar Hamoadim Rosh Hashanah 10.
The reason: This dialect of the blessing follows the dialect of the blessings of Kiddush and Haftorah of Rosh Hashanah. Although this is not the classical dialect of the Yom Tov blessing for candle lighting, nevertheless this was the custom of Beis Harav. [Igros Kodesh 6/125]
Other Opinions: The world is accustomed to recite the same blessing as any Yom Tov “Lehadilk Ner Shel Yom Tov”. The reason for this is because there is no difference between the Yom Tov of R”H and the other Holidays, and the only reason we conclude differently in prayer is because it needs to be Meiyn Hachasima. [Letter of 4th MarCheshvan 1976, printed in Shulchan menachem ibid]
 Siddur Tehillas Hashem; Mateh Efraim 581/54; 599/9
The source for reciting Shehechiyanu by Hadlakas Neiros as opposed to Kiddush: The Shulchan Aruch and earlier Poskim never mention that Shehechiyanu is to be recited during candle lighting. Nevertheless the women are accustomed to do so. Some Poskim negate this custom due to it not having any source in previous Poskim and due to other reasons. [Sheilas Yaavetz 107; Shaareiy Teshuvah 263/4; Birkeiy Yosef 263/1; Chesed Lealafim; Kaf Hachaim 263/40; See however Elya Raba 600/3 that mentions this custom] Nevertheless those women that are accustomed to do so are not to abort their custom, as this tradition dates back to previous generations. [Poskim ibid; Mateh Efraim 581/54; 599/9; Sheilas Yaavetz ibid “My wife herself would say the blessing by candle lighting and I desired to protest against her doing so although I held myself back as it does not contain a blessing in vain and it is a tradition of previous generations.”]
 Siddur Tehillas Hashem; Sefer Haminhagim p. 117 [English]
 Mateh Efraim 599/11; 625/33; Shevach Hamoadim p. 13 [4/1] in name of Rav Zalman Shimon Dworkin and the Toras Chesed of Lublin; Hakdama of the son of the Derisha to Tur Yoreh Deah 1; See Likkutei Sichos 24 p. 792 footnote 96.
 As the Mitzvah of lighting candles begins with the entrance of Yom Tov and it is hence improper for them to delay this Mitzvah. [Alef Lamateh 625/51]
 See Alef Lamateh 625/51; In order so they return from Shul with a set table that contains lit candles. [ibid]
 Mateh Efraim 599/9; Vayagel Yaakov 39; Luach Kolel Chabad; Hiskashrus 896
The reason: As even by women there is no source in Poskim to say the blessing by candle lighting, and it is only because of the time honored custom of women to do so that we allow them to say it then. [See Poskim in previous footnotes] However men who never accepted such a custom certainly are to say the blessing by Kiddush. [Vayagel Yaakov ibid]
 Mateh Efraim ibid
 Mateh Efraim 619/12; Sefer Haminhagim p. 128 [English]
 As this was their accepted custom. However Piskeiy Teshuvos 518/21 rules that they are to say the blessing by Kiddush. However after looking in his sources one clearly sees that the cases discussed there are regarding men and not women. Hence seemingly by women the custom should remain as always to say Shehechiyanu by candle lighting.
 See 263/8; Piskeiy Teshuvos 263 footnote 168
 Derech Hachaim 50/7; Ketzos Hashulchan 74 footnote 19; Customs in new Siddur Tehillas Hashem; Maharam Shick 119; Birchas Habayis 45/4
 Aruch Hashulchan 263/13; Toras Yekusiel 61; Ashel Avraham Butchach; Piskeiy Teshuvos 263/18
The reason: As men do not accept Shabbos right away upon lighting. [See 263/7]
 Some rule based on Admur [which does not differentiate between men and women] that men follow the same order as women and light before the blessing. [Ketzos Hashulchan 74 footnote 19; Customs in new Siddur Tehillas Hashem; To note the Nesiv Hachaim also did not argue on the ruling of Derech Hachaim ibid] Others however rule that according to [the M”A and] Admur [which states the above custom to first light in Lashon Nikeiva, in contrast to the wording of the Rama] men are to first say the blessing and then light. [Piskeiy Teshuvos ibid] Vetzaruch Iyun on the above Poskim that did not infer differently from Admur as seems clear from his wording and as writes Piskeiy Teshuvos.
 See Admur 514/14; Biur Halacha 514 “Ner”; Piskeiy Teshuvos 514/14
 Biur Halacha ibid; Piskeiy Teshuvos ibid footnote 70; See SSH”K 13 footnote 27
 Biur Halacha ibid; Piskeiy Teshuvos ibid
The reason: As one may light any candle in Shul as it is considered a Neir Shel Mitzvah. [514/14]
Other Opinions: Some Poskim rule one may never light a Yartzite candle on Yom Tov, even in Shul. [Daas Torah 514 in name of Imrei Eish] Some rule one may only do so through a gentile. [Kitzur SHU”A 98/1]
 Piskeiy Teshuvos ibid
The reason: As it does not add any light to the house even at night being that we have electricity. Thus it may not be lit as it is considered a light that serves no purpose which is forbidden to be lit on Yom Tov. [514/13]
 Biur Halacha 514 “Neir”
 Initially one is to light it near ones dining room table, thus giving it a use. However if this is not possible then one may light it in any area as it is considered a Ner Shel Mitzvah. [ibid]
 See Hiskashrus 896
 Rav Hendel of Migdal Eimek brought in Hiskashrus ibid