Kitzur Shulchan Aruch, Rabbi Shlomo Ganzfried
Chapter 79 : Laws of Maftir
Before the maftir is called to the Torah the half-Kaddish should be said. During the recitation of the kaddish, the seifer Torah from which the present reading was done and also the seifer Torah that will be used for the maftir reading should both be on the reading desk. And on a day that three sifrei Torah are used it is not necessary to place the first one [on the bimah].
The one who has maftir should not begin the berachos of the haftarah until after the one who rolls up the seifer Torah binds it in its wrapping cloth.
In the first berachah, after the words hanemarim be'emes [which were spoken in truth] Amein is not answered until the end, when the last word vatzedek is said, because it is all one berachah. Similarly, after the first segments of the concluding berachos, Amein is not said after the words emes vatzedek [true and righteous] because [the segment beginning with] ne'eman ata [you are faithful] is also part of this berachah. And because there are some people who mistakenly answer Amein in these places, it is better that the maftir not make any pauses there, in order to indicate that the berachah does not end there.
It is forbidden to speak when the maftir reads the haftarah.
According to the basic law, only the maftir himself should say the haftarah [aloud], and the congregation should repeat after him quietly. And the custom whereby the congregation reads aloud together with the maftir, stems only from ignorance, and this custom should be abolished. There are some people who say the haftarah so slowly that even after the maftir ends the haftarah and begins the berachos, they don't want to stop saying the haftarah. These people are acting improperly, because if they say it aloud, they, themselves, cannot hear the words of the beginning berachos of the maftir, and they also prevent their neighbors from hearing them. And even if they lower their voices, a little at the beginning of the berachos, still they themselves do not hear them. Therefore, the recommended practice is that as soon as you hear that the maftir concludes the haftarah and begins the berachos, even though you still did not finish, you should wait silently until the maftir concludes the berachos, and after that you should finish saying the haftarah. The maftir, too, should be careful not to begin the berachos until the noisy sound of the congregation has ended completely.
On a Shabbos when two sidrahs are joined, the haftarah is read of the second sidrah except when Acharei and Kedoshim are joined, then the haftarah Halo kivenei kushiyim, is read [Are you not as the children of the Kushim] In some chumashim it is noted that for the sidrah Vayishlach the haftarah, Vayivrach Ya'akov [And Yaakov ran] should be read, but this is an error, because this haftarah belongs to the sidrah Vayeitzei and the haftarah of Vayishlach is Chazon Ovadyah [The vision of Ovadyah].
When Rosh Chodesh occurs on Shabbos, the haftarah Hashamayim Kis'i is read [The heavens are My throne] If, by mistake, the haftarah of the weekly sidrah was read, [if the reader becomes aware of it] before he said the concluding berachos, he should also read Hashamayim kis'i and then say the berachos. If he only became aware of it after saying the berachos, he should say Hashamayim kis'i, without the berachos. If Rosh Chodesh occurs on a Sunday, the haftarah, Machar chodesh is read [Tomorrow is the new moon]. If [the reader] made an error, the same halachah applies as that of Shabbos Rosh Chodesh. If Rosh Chodesh occurs on Shabbos and Sunday, the haftarah Hashamayim kis'i is read.
On Shabbos of Chol Hamo'eid Pesach no mention is made in the berachos of the haftarah of anything relating to Pesach, either in the middle or at the end [of the concluding berachos]; but they should be concluded with Mekadeish haShabbos [Who sanctifies the Shabbos]. But on Chol Hamo'eid Sukkos (since the complete Halleil is then said and there is a difference in the daily sacrifices,) mention is made [of the Yom Tov] just as it is done on the Yom Tov days of Sukkos when they fall on Shabbos.
A minor who has reached the age of chinuch and knows to whom the berachos are directed, and can articulate the letters well, may be called up for maftir on Shabbos and on Yom Tov, except on parshas Zachor, on parshas Parah, and on Shabbos Shuvah. Likewise, on the seventh day of Pesach, when the shirah is read for the haftarah, it is customary not to call a minor to go up for maftir. Likewise, on the first day of Shavuos when the haftarah is read of the merkavah, the chariot in Ezekiel, it is customary to call up only an adult who is a Torah scholar. Likewise, on Shabbos Chazan it is customary to call up the Rabbi for maftir.
Reading the haftarah with berachos was instituted only after the reading of the Torah with berachos, and all the required aliyahs [has been completed]. But if a defect is found in the seifer Torah on a regular Shabbos, even during the seventh aliyah, and there was no other seifer Torah available, and therefore the concluding berachah was not said, or when the maftir is read, relating to the subject of the day, even if [the defect] is discovered in the maftir, then no berachos are said on the haftarah, but it should be read without berachos. But on a regular Shabbos, if after seven men were called, [all of whom recited] the berachos, the defect is found, whether while reading for the added aliyahs or while reading the maftir, it seems that the haftarah should be read with the berachos.