This year, we perform bedikas chometz on the night of the 13th of Nissan, therefore, after davening Ma’ariv with nacht [nightfall], one should return immediately home to check for chometz. Unless, one hasn’t yet recited kiddush levonah, in which case kiddush levonah would come first, as it is considered a mitzvah overes, a mitzvah which may pass (like we see in Shu”t Noda B’Yehudah, Orach Chaim 41).
It is forbidden to eat before performing bedikas chometz, however, a bechor who fasted all day and it is difficult for him to do bedikas chometz before eating, he may eat a little bit (a kebeitzah of bread or even lots of fruit, see 232:3) before performing bedikas chometz, or he should instruct someone else to do it for him and he may then eat (see Mishnah Berurah 470:6).
Bedikas chometz is carried out with a berachah, and one performs bittul chometz afterwards like every year (Mishnah Berurah 444:1). One should also make sure to check the room he plans to eat chometz in on erev Shabbos and Shabbos, and one should be careful to leave any chometz he plans on eating over the next two days in a safe place, out of reach from any children, to ensure they don’t get hold of it (see Shaar HaTziyun 434:4).
After bedikas chometz is carried out in shul, an announcement should be made that children should no longer bring any chometz into the shul (Chok Yaakov, 433:22).
Shopkeepers who plan on selling chometz after Thursday night, i.e. on Friday morning, there is no need for them to do bedikas chometz until they finish selling chometz.
The Shulchan Aruch HaRav (433:42) writes regarding a regular year, that there is no point in checking pockets of clothing that people plan to wear after doing bedikas chometz, as one may come to put chometz inside them after he finishes bedikas chometz (as one is still able to eat chometz until erev Pesach). Therefore, certainly in our case, when the shop still plans to sell chometz, there is no point in doing bedikas chometz. Even the Mishnah Berurah (433:47) who argues and says that one should check pockets, our case is worse, as putting chometz inside pockets after checking them is only a doubt, whereas the case of the shopkeeper is definite, so what does bedikas chometz help (Nitei Gavriel, Hilchos Erev Pesach Shechal B’Shabbos 3:14)
