75:1 A person must stop performing prohibited acts of labor (melacha) and light candles at least half an hour before the stars appear. If they said "Mizmor Shir l'Yom haShabbos" (Psalm 92) in the community's shul, even as much as two hours before nightfall, then Shabbos applies even to those not present and all must refrain from prohibited acts of labors. (Mishnah Brurah 261:31 says when they recite the words "bo'i kallah" in Lecha Dodi.) Even a visitor from another city is obligated in Shabbos once the congregation has recited this Psalm. If a city has more than one shul, the actions of one do not affect the members of the other. (Similarly, if the majority of the congregation is not in shul, the actions of the minority do not impose Shabbos upon the majority - MB 263:51.)
75:2 It is a mitzvah to light many candles in honor of Shabbos. Some have the custom to light ten candles, while others light seven. At the very least, one should have two candles corresponding to "zachor" and "shamor," the Torah's commands to remember and to observe Shabbos (Exodus 20:8 and Deuteronomy 5:12, respectively). In a pinch, however, one candle is sufficient. The candles should be long enough to ensure that they burn at least until the evening meal is finished. A person should try to buy beautiful candles as per Talmud Shabbos 23b, which tells us that a person who makes a habit of trying to have beautiful candles for Shabbos will merit having sons who will be Torah scholars. This is based on Proverbs 6:23, "A mitzvah is a candle and the Torah is light." The implication is that the light of Torah is brought about through the candle of a mitzvah. Accordingly, it is appropriate for a woman to pray when she lights candles that Hashem grant her sons who will excel in Torah. It is also appropriate for a woman to donate a little money to charity before lighting Shabbos candles. There is a practice for women who have no children, or who are having difficulty raising their children, to recite I Samuel 1, 2:1-10, the haftarah for the first day of Rosh Hashana (including Chana's prayer for a son) after lighting Shabbos candles. It's recommended that the woman understand what she is reading and that she say the passage with concentration.