Sacramentals are such things as the Sign of the Cross, Holy Water, Scapulars, Holy Medals, and Symbolic gestures such as kneeling and blessing, and Sacred Signs such as fire, candles and ashes.
Are Sacramentals just a superstition? This short article explains how we should approach their use.
An Online Book by Fr Anthony Tonne which covers everything you could want to know about Sacramentals.
Some questions on Sacramentals form the St. Charles Borromeo Catholic Church in Mississippi.