The normal salaah with sunnah is the following, which salafi and hanafi follow and others who want more ajr.
Farj: 4 = 2 sunnah 2 fard
Zuhr: 12 = 4 sunnah 4 fard 2 sunnah 2 nafl
Asr: 8 = 4 sunnah 4 fard
Magrib: 7 = 3 fard 2 sunnah 2 nafl
Isha: 17 = 4 sunnah 4 fard 2 sunnah 2 nafl 3 witr 2 nafil
Number of rakats in each obligatory (fard) salah:
As for what you should do minimum, i would recommened this...
The Prophet (sallallahu alayhi wassalam) said:
"Allaah will build a house in Heaven for whoever is diligent in observing 12 Sunnah Rak'aat (as follows): 4 Rak'aat before and 2 after the Dhuhr (Midday) Prayer, 2 after the Maghrib (Sunset Prayer), 2 after the ‘Ishaa’ (Evening) Prayer and 2 before the Fajr (Dawn) Prayer."
Hadith sahih narrated by at-Tirmidhi No. 379 and by others. Hadith No. 6183 in Sahih al-Jaami
Allaah’s Messenger (sallallahu alayhi wassalam) said:
"A house will be built in Heaven for one who prays 12 Rak'aat in a day and evening as follows: 4 Rak'aat before and 2 after the Dhuhr Prayer, 2 after the Maghrib Prayer, 2 after the ‘Ishaa’ Prayer and 2 before the Fajr Prayer."
Narrated by at-Tirmizi under No. 380. He said: The Hadith narrated by ‘Anbasah quoting Umm Habibah in this chapter is a hassan and sahih hadith. It is under No. 6362 in Sahih al-Jaami’
The Prophet (sallallahu alayhi wassalam) said:
“Whoever prays twelve rak’ahs during the night and day, a house will be built for him in Paradise: four before Zuhr and two after, two rak’ahs after Maghrib, two rak’ahs after ‘Isha’ and two rak’ahs before Fajr prayer.”
Narrated by al-Tirmidhi, no. 380; classed as saheeh by al-Albaani in Saheeh al-Jaami’, 6362