The Shulhan Aruch (Orah Haim 250; listen to audio recording for precise citation) writes that one should arise early in the morning on Erev Shabbat in order to begin making preparations for Shabbat. Halacha affords such great importance to Shabbat preparations that, as the Mishna Berura (commentary to the Shulhan Aruch by Rabbi Yisrael Meir Kagan, 1839-1933) writes, one may purchase food for Shabbat before praying Shaharit on Friday morning, if he fears that the food will not be available later. In such a case, where there is concern regarding the availability of food, one should recite Shema, go to the store to purchase food for Shabbat, and then pray.
The Shulhan Aruch adds that even if a person has many servants working for him who could complete the Shabbat preparations, he should nevertheless involve himself in some way in preparing for Shabbat, as a demonstration of honor to the day.
Kabbalistic tradition teaches that when a person selects a food item for Shabbat, he should verbally declare, "Li'chvod Shabbat Kodesh" – "For the honor of the holy Shabbat."
The Kaf Ha'haim (Halachic work by Rabbi Yaakov Haim Sofer, 1870-1939) writes (250:5) that when a person perspires as a result of his Shabbat preparations, the perspiration has the effect of erasing his sins from his record. Just as the tears of remorse and Teshuva erase one's transgressions, so does the sweat produced by his Shabbat preparations have this same effect of eliminating his sins. The Kaf Ha'haim adds that one should not consider it beneath his dignity to exert himself in the Shabbat preparations; quite to the contrary, it is most honorable and dignifying to be involved in this great Misva.
Later (250:8), the Kaf Ha'haim records the practice mentioned in the Talmud Yerushalmi to taste the foods prepared for Shabbat. In order to ensure that the food is tasty as befitting Shabbat, one should make a point of tasting on Erev Shabbat every dish intended to be served during Shabbat. Observing this practice helps ensure a person long life. The Kaf Ha'haim (250:9) further writes that the husband should arrange the candles that the wife will light in honor of Shabbat, and that the home – including the outside porch – should be properly swept and cleaned before Shabbat. Husbands as well as wives should be involved in the process of cleaning the home for Shabbat, and nobody should consider such activity beneath his dignity.
