Search your house for any leavened food or crumbs the night before first seder night. If the first seder begins Saturday night, you must search for chametz on Thursday night.
 

The only time when matza must be eaten to fulfill the commandment of eating matza is on seder night(s). There may be a mitzva to also eat matza on the other days of Passover (but there are conflicting opinions about that).
However, men must eat matza in order to fulfill the commandment of eating two meals a day on each of the festival days.
 

Pesach, matza, and maror should be read and explained with special attention.
Reason They are the main parts of the seder and of the commandment to have a seder.
 

Break the middle of the three matzas and hide the larger part.
Reason As with most of the actions we do at the seder, this is to evoke curiosity in children. It also represents the idea that poor people can't afford a whole loaf of bread or might save some food for the next day.

1 Revi'it = Usually 3.3 fl. oz. (99 ml); but 4 fl. oz. (119 ml) for:

• Any food requiring bracha achrona.
• The four cups of wine at the seder.
• Kiddush for Shabbat and Jewish festival nights.

 
1 Log = Volume of 6 eggs = 4 Revi'ot (a revi'it is 1/4 of a log)  
1 Kab = 4 Login  
1 Se'ah = 6 Kabin
 
40 Se'ah = Volume equivalent to 3 cubes, 24 ½” (61 cm) on each side; minimum requirement for mikva = about 192 gallons/750 liters  

1 fl. oz. = 1.77 cu. inch (about the size of a golf ball)

Dip the karpas in the salt water and say the blessing borei pri ha'adama; keep in mind that this blessing will also apply to the bitter herbs you will eat later in the seder.

The only time you must use shmura matza is for the four commandments of motzi, matza, koreich, and afikoman.

K'zayit is variously defined as being the volume of 1/3, ½, or 1 whole egg; 0.6 - 1.9 fl. oz. (18-56 ml), depending on the application.

• K'zayit for Seder Matza and Afikoman:  1.9 fl. oz. (56 ml) of matza.
• K'zayit for Bracha Achrona and Birkat HaMazon: 1.3 fl. oz. (39 ml, or 1/6 cup) of solid food.

Beitza, K'Beitza = 1.9 fl. oz. (56 ml); an egg size by definition.

If a girl age 12 or up or a woman forgets to say ya'aleh v'yavo for the Jewish festival or Rosh Chodesh amida, she must repeat the prayer.  She does not repeat ya'aleh v'yavo in any birkat ha'mazon except the two seder nights.

To do Shabbat kiddush,

• Say, or hear, the Shabbat kiddush blessings/segments, and
• “Establish a meal” (kovei'a se'uda).

For details, see How To Do Shabbat Evening Kiddush  or How To Do Shabbat Daytime Kiddush.
NoteThere is never any requirement on an indvidual to drink kiddush wine (except at the Passover seder), but the kiddush wine must be drunk by one or more persons.

When saying birkat ha'mazon, you must repeat birkat ha'mazon if you forgot:

• Retzei on the first two meals of Shabbat.
• Ya'aleh v'yavo on the first two meals of any Jewish festival day (women only repeat if they forgot it at the Passover seder).

Never repeat birkat ha'mazon if you forgot additions for:

• Rosh Hashana (during the daytime) or
• Rosh Chodesh.

Say the blessing “al achilat maror.”
Dip the maror into the charoset and shake off all but a little bit of the charoset.
Do not lean when eating the maror.

A siyum can be held anytime a book of Torah or Talmud or any other holy book (sefer kodesh) has been studied for a long time; three months or longer is a good guideline. Simply reading through a book does not qualify; you must study it and understand it.

We are required to eat two meals on Jewish festivals, each preceded by kiddush, one in the evening and one in the morning. For both meals for each Jewish festival day (and all three meals on Shabbat), say ha'motzi over two complete loaves of bread, each of which is at least 1.3 fl. oz. in volume. 

Source of Saying Jewish Festival Kiddush
Some kiddushes are commanded by the Torah (d'oraita); the others are from Chazal (d'rabanan), as follows:
Kiddush d'Oraita

• First night of Jewish festivals
• Night of seventh day of Passover
• Night of Shmini Atzeret.

Kiddush d'Rabanan

• First day of Jewish festival
• Second night of Jewish festival
• Second day of Jewish festival
• Seventh day of Passover
• Eighth night of Passover
• Eighth day of Passover
• Shmini Atzeret day
• Night and day of Simchat Torah.

Source of Jewish Festival Kiddush Location
Saying Jewish festival kiddush at the place where you will eat your meal is a rabbinical (d'rabanan) enactment.
Jewish Festival Kiddush-Meal Quantities: Evening

• For evening kiddush for a first-night (d'oraita) Jewish festival, a minimum of 4 fl. oz. (119 ml) of wine must be blessed on and at least half must be drunk.
• For evening kiddush for a second-night (d'rabanan) Jewish festival, a minimum of 3.3 fl. oz. (99 ml) of wine must be blessed on and at least 2.0 fl. oz. must be drunk.
• For the evening meal, as on the first two Shabbat meals and for all required Jewish festival meals, a minimum of 1.9 fl. oz. (56 ml) of bread must be eaten within four minutes.

Eating Requirements for Jewish Festival Morning Kiddush
There are two separate eating requirements during the daytime. They may be combined (say/hear kiddush and start the main meal right away) but are often done separately (say/hear kiddush and then eat some light foods and beverages; the main meal is eaten later in the day).
Note Since eating and drinking requirements on all morning kiddushes (both Shabbat and Jewish festivals) are d'rabanan, the required beverage amount for morning kiddush is only 3.3 fl. oz. (99 ml) instead of the d'oraita 4 fl. oz. (119 ml) (which is required for kiddushes for Shabbat evening and all first-night Jewish festivals).

• Morning kiddush requires a halachically legal “meal” with these elements:
  • Blessing on a minimum of 3.3 fl. oz. (99 ml) of wine (or other beverage),
  • Someone's drinking at least half the beverage, followed by
  • Eating at least 1.3 fl. oz. (39 ml, or 1/6 cup) of some type of mezonot within four minutes. 
    Note If you drink at least 3.3 fl. oz. (99 ml) of wine within 30 seconds, you do not need to eat mezonot.
    Note You do not need to drink the wine or other kiddush beverage to fulfill “establishing a meal.” You may hear kiddush and then simply eat the required amount of bread or mezonot. This applies to Shabbat or Jewish festivals, evening or morning.
     

 

• The real meal (kovei'a se'uda) requires eating at least 1.9 fl. oz. (56 ml) of bread (or matza during Passover!) within four minutes. It must include enough food to satiate. 
  Note You can simultaneously fulfill the requirement to “establish a meal” and to “eat a meal” by eating one (the same) piece of bread.

Any adult Jew, male or female, may say kiddush for him/herself and, as long as he/she still needs to say kiddush for him/herself, may include any other Jews of any age or gender.
Any Jewish male, 13 years old or older, may say kiddush for anyone else, either gender and any age, even if he has already fulfilled his personal requirement of saying kiddush.
Any Jewish female, 12 years old or older, may say kiddush for any other females but not for men, except that on the 2 Passover seder nights, a Jewish female who is at least 12 years old may even say kiddush for men, if the men are not able to say it for themselves. (Women may also say kiddush for men on Shabbat evening).
Reason Any person who is obligated to fulfill the mitzva of kiddush may say it for another person.  It is questionable whether women are obligated to say (or have said for them) Jewish festival morning kiddush.