The minimum number of rak’ahs to be prayed is two. The most that the Prophet (SAW) performed was eight rak’ahs. Personally, I pray 4 rakaats now after praying 2 rakaats for 20 years already. Sometimes when there are time constraints, two rakaats is so convenient.
Narrated from Abu Hurayra by al-Tirmidhi, Ibn Majahm and Ahmad.
From the above , the core of it are these two du'as.
Du'a solatul Dhuha ~
اَللهُمَّ اغْفِرْ لِيْ وَتُبْ عَلَيْ إِنَّكَ أَنْتَ التَّوَّابُ الرَّحِيْم
100 times ... (Bukhari)
or اَللهُمَّ اغْفِر لِيْ وَارْحَمْنِيْ وَتُبْ عَلَيْ إِنَّكَ أَنْتَ التَّوَّابُ الْغَفُوْر
100 times..... (Baihaqi)
It is clear that Dhuha prayer is very important for the faithful. It is important not because - as many have perceived - Dhuha prayer has to do with the search for sustenance, but it is important because of the oath of God in the Qur'an.