Barech

1. Before Birkhat HaMazon, one should fill the third cup of wine, and say Birkhat HaMazon over it. After Birkhat HaMazon, one should recite ha-gefen and drink while leaning.
2. One should recite Birkhat HaMazon while holding the cup of wine.
3. One shouldn’t recline during Birkat HaMazon rather one should sit up and say it with concentration.
4. In Birkat HaMazon, one should make sure to say Yaaleh VeYavo mentioning Pesach and if one forgets one has to repeat Birkat HaMazon.
5. The fourth cup is filled after Birkhat HaMazon.

Sources

Time	Topic
Before Pesach	Month of Nissan - Shabbat HaGadol - Bedikat Chametz - Biur Chametz - Bitul Chametz - Tanit Bechorot - Erev Pesach - Selling Chametz - Erev Pesach That Fell out on Shabbat - Candle Lighting on Yom Tov - Kashering the kitchen for Pesach - Which foods, medications, cosmetics, and toiletries are Chametz? - Kitniyot - Chametz of a non-Jew - Owning Chametz on Pesach
The Seder	Kaddesh - Urchatz - Karpas - Yachatz - Maggid - Rachsa - Motzei Matzah - Maror - Korech - Shulchan Orech - Tzafun - Barech - Hallel of the Seder - Nirtzah - Kriyat Shema Al HaMitah
Pesach	- Setting the Table (The Seder plate) - Arvit of the night of Pesach - Leaning during the Seder - Required Amount of Matzah and Wine for the Seder - The four cups of wine - Matzah
After Pesach	Issru Chag - Chametz which a Jew owned on Pesach - Pesach Sheni