The Gemara (Pesachim 106a) states, “Our Sages taught: ‘Remember the day of Shabbat to sanctify it’-remember it upon wine when it enters.” This means that there is a positive Torah commandment to verbally sanctify the Shabbat at its entrance. This remembrance is done by reciting words of praise and sanctification. The Members of the Great Assembly drafted the text of the Kiddush which we recite upon a cup of wine. (See Berachot 33a)
There is a rabbinic enactment for this remembrance, i.e. the Kiddush, to be recited on a cup of wine. Our Sages supported this idea from verses which refer to the remembrance and wine, such as “His memory is like the wine of Lebanon” and “We shall remember your love more fragrant than wine”. Thus, our Sages enacted Kiddush to be recited upon wine and after the Kiddush, one must drink the appropriate amount of wine, which is a majority of a Revi’it, i.e. approximately 1.5 fluid ounces (since a Revi’it is approximately 2.8 fluid ounces) in one shot. If one does not have wine or if one cannot drink one wine because it is harmful to him, one can recite Kiddush on bread by first washing one’s hands (Netilat Yadayim) and then reciting the text of the Kiddush upon the bread as one would one on wine; one must substitute the “Boreh Peri Ha’Gefen” blessing with “Hamotzi Lechem Min Ha’aretz”. If one has wine but one cannot drink a majority of a Revi’it but there is a family member there that can drink this amount, one may recite Kiddush, taste a small amount of the wine, and then pass the cup to another member of the household who will then proceed to drink the prescribed amount.
The Poskim write that when one arrives home on Friday night following services in the synagogue, one should immediately recite Kiddush on wine, for our Sages enacted that one must sanctify the Shabbat “at its entrance”, i.e. as close as possible to the onset of Shabbat. There are other reasons for reciting Kiddush promptly on Friday night as opposed to pushing it off.
It is therefore a good idea for one to instruct one’s family to have the table set on Friday night so that when one returns home from the synagogue, one will be able to recite Kiddush immediately. Nevertheless, if one’s household is not careful about this matter for whatever reason, one should take extreme caution not to make a fight because of this matter since it is a terrible sin to become angry needlessly. This is especially true on Shabbat when one should not become angry at all.
Before Kiddush, it is customary to sing “Shalom Alechem Malachei Ha’Sharet”. One should say “Melech Malchei Ha’Melachim” and not “Mi’Melech Malchei Ha’Melachim”. One should then recite the last chapter of Mishlei, “Eshet Chayil”. One should then recite the text of Kiddush printed in Siddurim.