"All Israel is responsible for one another." (Talmud Shavuot 39a).
It is customary to give tzedakah (charity) by putting a few coins in a Tzedakah box before lighting the Shabbat candles. This money is for the purpose of tikkun olam, or the "repair of the world." Many families place the Tzedakah box next to the Shabbat candle holders to remind them to perform this mitzvah. Encourage even the youngest of your children to contribute a coin or two for the betterment of the world!
When money is put into the Tzedekah box, following blessing is customarily recited:
Blessed art thou, Lord our God, Master of the universe, who hast sanctified us with thy commandments, and commanded us about the Tzedakah.