Tehillim
Early in the morning, we gather in shul to recite the entire Tehillim with a minyan. Following Tehillim, a maamar (that can be understood by everyone) should be studied for around an hour, followed by davening.
“Make sure to study a parshah of Chumash with Rashi every day, to say Tehillim every day, and to complete the Tehillim on Shabbos Mevarchim. It is crucial for you, your children, and your grandchildren” (Hayom Yom, 25 Shevat).
“The takanah to recite Tehillim on Shabbos Mevarchim is not only relevant to those who follow our nusach. Ahavas Yisrael demands that we should try to have it instituted in every shul, no matter the nusach it follows” (Igros Kodesh of the Frierdiker Rebbe vol. 2, pp. 523-524).
For more on saying Tehillim on Shabbos Mevarchim, see below, “Hosafos.”
Krias hatorah
The haftorah of Machar Chodesh is read (I Shmuel 20:18-20:42).
Blessing the new month
It is proper to know when the molad will be before blessing the new month. This month, the molad will be on Sunday morning at 4:49 a.m. and 15 portions.
The chazzan stands, holding a Sefer Torah, and leads the congregation with Mi shebeirach. It is customary for the congregants to stand as well.
Rosh Chodesh Kislev will fall out on Sunday and Monday.
We don’t say Av Harachamim.
Shabbos Mevarchim is a day to farbreng, ideally in shul. For more on Shabbos Mevarchim farbrengens, see below, “Hosafos.”
Minchah
We don’t say Tzidkas’cha, due to it being Erev Rosh Chodesh.
Say Yaaleh Viyavo during Maariv tonight. See below, “Hosafos,” for the laws that apply if you forgot to say Yaaleh Viyavo.
