Adhaan(colling to Sallat) 

The Adhaan and Iqaumah are Sunnat Muakkidah for:

a. Fardh Salaat and Jumuah.
b. For Ada (schedule times) and Qaza (after time)
c. For one who is in his hometown and a Musafir (traveler according to Shariah).
d. For men, but it is Makrooh for women.

“Allaahu Akbar” is said four times at the beginning, and twice at the end.

 No undue pulling should be made of the two Shahadats.

In the Adhaan of Fajr “As Salaatu Khayrun Minan Nawm” is to be added twice after “Hayya alal Falah”.

In Iqaumah, “Qad Qaumatis Salaatu” is added twice after “Hayya alal Falah”.

In Adhaan, every sentence is said with a pause but in Iqaumah it is said quickly.

Adhaan is not valid in any other language other than Arabic.

1.The person who calls out the Adhaan is called a Muazzin.

2. It is Mustahab that the Muazzin be pious, one knowing the Sunnat of Adhaan and the proper times of Salaat.

3. He should be in the state of Wudhu and face the Qibla except if he mounted on an animal or (out of necessity ) on a train etc.

4. It is Mustahab that he inserts his two fingers in his ears, and turns his face to the right side when saying, “Hayya alal Salaah”, and to the left side when saying, “Hayya alal Falaah”.

He may turn completely in the dome if the sound does not reach in all directions.

The Adhan and Iqaumah should be separate to allow the regular Musallees to present themselves comfortably for congregation Salaat but at the same time the Mustahabh time
of Salaat performance must not be missed.

 Time between Adhaan and Iqaumah of Magrib should be the time taken to recite three Ayats of the Quraan or one long verse or the time taken to walk three steps.

After the Adhaan one can, in order to gather people for Salaat  call them by saying “Salaat, Salaat, O performers of Salaat’.

It is Makrooh:

a. To call the Adhaan in a singing tone.
b. Call Adhaan without wudhu or ghusal.
c. By a boy who cannot understand.
d. By an insane or drunk person.
e. By a woman.
f. By a faasiq (disobedient Muslim).
g. By one sitting.
h. Talking during Adhaan and Iqaumah.
i. To give Adhaan and Iqaumah of Zuhr Salaat in a town only on Fridays.

It is Mustahab to repeat the Adhaan while the Muazzin spoke but not the Iqaumah.
 Both (Adhaan and Iqaumah) will be made for Qaza Salaat.

 Likewise, both will be made for the first of several Qazas.

 It is Makrooh to omit the Iqaumah, but the Adhaan must be only performed for the first one provided that these are performed at one time.

source: Taleem ud Deen (Hanafi), Mufti Afzal Hoosen Elias.