Passover holiday candles are lit by the (eldest) woman of the house no later than 18 minutes before sundown on Nisan 14 (i.e., on Erev Pesach). After kindling the candles, she waives her hands over the flames three times (as if welcoming in the holiday), and covering her eyes with her hands (so as not to see the candles burning) says:
“Blessed art thou, Lord our God, Master of the universe, who sanctifies us with Your commandments, and commanded us to kindle the light (of shabbat and of ) the holiday.”
Note that if Pesach occurs on Shabbat, you insert “Shabbat v’shel” before the ending to yield: “...Shabbat v’shel yom tov.”
The Shehecheyanu Blessing
The Shehecheyanu blessing is also recited at this time: