Repeat what the muazzin says, except for when he says: حَيَّ عَلَى الصَّلاَةِ وَحَيَّ عَلَى الْفَلَاحِ.Here you should says: "There is no might and no power except by Allah".
لَا حَوْلَ وَلَا قُوَّةَ إِلَّا بِاللّهِ
Laa hawla wa laa quwwata 'illaa billaah.
One should then send prayers on the Prophet (saws) after answering the call of the muazzin.
اللّهُمّ صَلّ عَلَى مُحَمّدٍ وَآلِ مُحَمّدٍ
allahumma salli 'ala muhammad wa aali muhammad
اللَّهُـمَّ رَبَّ هَذِهِ الدَّعْـوَةِ التَّـامَّةِ، وَالصَّلَاةِ القَـائِمَة، آتِ مُحَـمَّداً الوَسِيـلَةَ وَالْفَضِـيلَةَ، وَابْعَـثْهُ مَقَـامـاً مَحْـمُوداً الَّذِي وَعَـدْتَهُ، إِنَّـكَ لَا تُـخْلِفُ المِيـعَادِ
Allaahumma Rabba haathihid-da 'watit-taammati wassalaatil-qaa'imati, 'aati Muhammadanil-waseelata walfadheelata, wab 'ath-hu maqaamam-mahmoodanil-lathee wa'adtahu, ['innaka laa tukhliful-mee'aad]
O Allah, Lord of this perfect call and established prayer. Grant Muhammad the intercession and favor, and raise him to the honored station You have promised him, verily You do not neglect promises.
One should also supplicate for himself during the time between the azan and the iqamah as supplication at such time is not rejected.
jazakumullahu khair.
