Preparing for Shabbat
This is not a chapter on how to properly observe Shabbat. Rather, it is a chapter on how to properly observe Erev Shabbat, Friday. Indeed, there is an entire array of laws and customs on how to maximize our Fridays in preparation for Shabbat. Even one who has servants at his disposal is obligated to personally tend to at least some of the Shabbat preparations himself. 
Preparing food for Shabbat
- One should make sure to buy one's food for Shabbat on Friday and not before unless one feels that one won't be able to find those items if one only goes to the store on Friday. 
- One must pray before going to buy one's food for Shabbat and if one regularly learns one should not change one's practice and only buy the food afterwards unless there's a fear that one will loose the opportunity to buy the food in which case one should delay one's learning.
- If there's a fear that if one waits until after davening one may loose the opportunity to buy one's food for Shabbat before prayer but one should at least say Shema beforehand. 
- Even if one had many helpers or family members preparing for Shabbat one should make an effort to personally be involved in preparing for Shabbat. 
- There's a righteous practice to taste the food for Shabbat on Friday in order to know whether it's spiced and tasty. 
Eating on Friday
Having a festive meal
- On Friday one may not make a festive meal which one normally wouldn't have during the week. 
- Strict halacha permits one to eat an amount that’s normal for a weekday meal, however, one should refrain from beginning a meal which is normal for a weekday meal from the 9th hour (Shaot Zmaniot) in the day. 
- In the winter months when the Shaot Zmaniot (halachic hours) are short one should refrain from having a meal too close to Shabbat so that if one has a meal one will still have an appetite going into Shabbat. 
- It’s totally permissible to have a snack the entire day of Friday and there’s no preference not to eat after 9 hours. 
- Past the 9th hour, one shouldn’t drink so much that one won’t be hungry for the Shabbat meal. 
Brit Milah or Pidyon HaBen on Friday
- One may have the festive meal of a Brit Milah or Pidyon HaBen on Friday. However, it is preferable to make the meal in the morning (before Chatzot, halachic midday). 
Wedding on Friday
- Similarly, a wedding which took place on Friday may be accompanied by a feast. However, it's preferable to push off the feast until Shabbat or another day. 
Engagement party on Friday
- One should not make a feast for an engagement party on Friday. 
- Rivevot Ephraim 1:181, S"A OC 250:1, Amot Shel Halacha (Rabbi Ari Enkin)
- Gemara Shabbat 117b writes that a pperson should get up early on Friday to prepare for Shabbat. So rules S"A 250:1. Mishna Brurah 250:2 explains that the reason is that by purchasing food for Shabbat on Friday it's more recognizable that one is preparing for Shabbat than if one were to buy the food on Thursday. He adds that if there's a fear that one won't be able to buy one's food on Friday then one may do so on Thursday. So rules Menuchat Ahava (vol 1, 2:1).
- Mishna Brurah 250:1, Menuchat Ahava (vol 1, 2:1)
- Mishna Brurah 250:1, Menuchat Ahava (vol 1, 2:1)
- S"A 250:1
- Magan Avraham 250:1, Menuchat Ahava (vol 1, 2:3)
- S"A 249:2. The Shulchan Aruch's reason to forbid the festive meal is that it takes away from Kavod Shabbat as one should go into Shabbat with an appetite. The Mishna Brurah 249:10 quotes another reason; if one is involved in preparing a festive meal it'll prevent one from preparing for Shabbat.
- S”A 249:2 writes that halachically it’s permissible to have a meal the whole day because we hold like Rabbi Yose in Pesachim 98b. However, even Rabbi Yose agrees that establishing a meal is forbidden after 9 hours.
- Mishna Brurah 249:16
- S”A 249:2 who writes that one can have a snack the whole day and preferably one shouldn’t have a normal meal after 9 hours. Mishna Brurah 249:15 writes this explicitly that a snack is permitted the whole day.
- Mishna Brurah 249:14 writes that the permit to have snacks the whole day doesn’t include drinks. He concludes that one should at least be careful from 9 hours and on not to have too much that one won’t be hungry for the Shabbat meal.
- Rama 249:2 writes that if the meal of a mitzvah that has a set time such as Brit Milah and Pidyon HaBen one can have the meal even on Friday. Mishna Brurah 249:12 adds that even if the Brit Milah was delayed because the child was sick or a Pidyon HaBen which was not performed on the 30th day, nonetheless the feast may be held on Friday. Yalkut Yosef (Shabbat vol 1 pg 531) agrees.
- Mishna Brurah 249:13, Yalkut Yosef (Shabbat vol 1 pg 62)
- Mishna Brurah 249:9
- S"A 249:2 writes that one should not make a feast even for an engagement which is a seudat mitzvah. However, the Mishna Brurah 249:9 writes that this is only true if the engagement took place on a different day however, if the engagement actually took place on Friday the feast may be held. Nonetheless, the Mishna Brurah concludes that the engagements that we perform nowadays are not halachically binding as they were in the times of the gemara and so it's not considered a seudat mitzvah which would permit a feast on Friday.