Hilchos Pesach – 19 / Erev Pesach

1. It is forbidden by Rabbinic decree to eat matzah on Erev Pesach, beginning from dawn of the day before Pesach. The purpose of this is to make the eating of the matzah at night clearly for the sake of the mitzvah. Likewise, it is forbidden to eat even “puffed” or “folded” matzah on Erev Pesach though we are strict about such matzos and we treat them as chametz and do not eat them on Pesach. Some have a custom to not eat any matzah starting from Rosh Chodesh Nissan (Shulchan Aruch and Mishnah Berurah  471).
2. It is also forbidden to feed matzah to young children on Erev Pesach, unless they are so young that they will not understand anything that will be recounted to them at night about the Exodus from Egypt (ibid.).

Hilchos Pesach – 20 / The Seder Night

1. Women are obligated in all the mitzvos that apply on the Seder night. This includes eating matzah, maror (bitter  herbs), recounting the story of the Exodus from Egypt and drinking the four cups of wine. Although these are all time-bound mitzvos from which women are ordinarily exempt, nevertheless they are obligated in these mitzvos because they too were part of the miracle of the Exodus (Shulchan Aruch and Mishnah Berurah  472).
2. It is a mitzvah to give the children nuts and the like to prompt them to notice the changes of this night and ask the Mah Nishtanah(“Why is this night different?”). They should be stimulated to stay awake and not fall asleep until after the paragraph of Avadim ha-yeenu (“We were slaves….”), so that they hear the essence of the story of the Exodus (ibid.).

Hilchos Pesach – 21 / Reclining

1. Reclining [at the Seder] is not to be done with the person lying on his back or face down since this is not a manner of freedom. Nor should one recline on his right side because he will need his right hand to hold the food he is eating [which would be impossible if he is resting on it] and so that the food not go down the windpipe (trachea) instead of the gullet (esophagus). Therefore, one should recline on his left side. Even a left-handed person should lean on his left side; however, after the fact, if a left-handed person leaned on his right side, he fulfilled his obligation (Shulchan Aruchand Mishnah Berurah  472).

2.    When reclining, one needs to be leaning on a surface such as the bed or bench. After the fact, if one leaned on another person sitting to his side, it is a valid reclining. But if one reclined on his own knees, this is not considered reclining, as it appears as though he is worrying (ibid.).