Find candle lighting times here.
The blessing, found in any edition of the High Holiday prayerbook is:
בָּרוּךְ אַתָּה ה׳ אֱלֹהֵֽינוּ מֶֽלֶךְ הָעוֹלָם אֲשֶׁר קִדְּשָֽׁנוּ בְּמִצְוֹתָיו וְצִוָּֽנוּ לְהַדְלִיק נֵר שֶׁל יוֹם הַכִּפּוּרִים.
Barukh attah adonai, eloheinu, melekh ha-olam, asher kidd’shanu b’mitzvotav v’tzivvanu l’hadlik neir shel yom ha-kippurim.
Praised are You, Adonai, our God, Sovereign of the universe, who, sanctifying us with divine commandments, has commanded us to light the Yom Kippur lamp.
If Yom Kippur coincides with Shabbat, the blessing concludes:
…לְהַדְלִיק נֵר שֶׁל שַׁבָּת וְשֶׁל יוֹם הַכִּפּוּרִים.
…l’hadlik neir shel shabbat v’shel yom ha-kippurim
…has commanded us to kindle the Shabbat and Yom Kippur lamp.
In either event, it is followed by the She-heḥeyyanu (also written as shehechianu) blessing:
בָּרוּךְ אַתָּה ה׳ אֱלֹהֵינוּ מֶלֶךְ הָעוֹלָם שֶׁהֶחֱיָנוּ וְקִיְּמָנוּ וְהִגִּיעָנוּ לַזְמַן הַזֶּה.
Barukh attah adonai, eloheinu, melekh ha-olam, she-heheyyanu, vekiyamanu, vehigiyanu lezman hazeh.
Praised are You, Adonai, our God, Sovereign of the universe, who has given us life, sustained us, and brought us to this occasion.
In addition, a special Yizkor candle is lit just prior to the formal Yom Kippur candles by those who will be remembering loved ones no longer living.
There is no blessing recited on the kindling of this candle, although many prayerbooks include appropriate devotional material to recite just before lighting the memorial candle.
Adapted with permission from The Observant Life.