The time for this is 12 to 15 minutes after Sunset. It is better to offer 'Magrib Namaz' and then break one's fast, preferably with water, milk or dates.

The following Dua may be recited at the time of breaking one's fast:

supplication

ALLAAHUMMA LAKA S'UMTU WA A'LAA RIZQIKA AFT'ARTU WA A'LAYKA TAWAWKKALTU

O my Allah, for Thee, I fast, and with the food Thou gives me I break the fast, and I rely on Thee

Ameer ul-Moomineen Ali Ibne Abi Taalib (A.S.) used to recite the following du'a before Iftaar:

supplication

BISMILLAAH ALLAAHUMMA LAKA S'UMNAA WA A'LAA RIZQIKA AFT'ARNAA FA-TAQABBAL MINNAA INNAKA ANTAS SAMEE-U'L A'LEEM

In the name of Allah, O Allah, we fast, and with the food Thou gives us we break the fast, an obligation we fulfill, and Thou art Hearer, Knower

While taking the first mouthful recite:

supplication

BISMILLAAHIR RAH'MAANIR RAH'EEM YAA WAASI-A'L MAGHFIRATI IGHFIR LEE

In the name of Allah, the Beneficent, the Merciful, O He whose indulgence is boundless, forgive me

Recite Soorah Al-Qadr.
Give alms in the name of Allah.

Every night do the following:

Recite Soorah Al-Qadr 1000 times.
Recite Soorah Al-Dukhaan 100 times.
Recite

supplication

ALLAAHUMMA RABBA SHAHRI RAMAZ'AANAL LAD'EE ANZALTA FEEHIL QUR-AANA WAFTARAZ'TA A'LAA I'BAADIKA FEEHlS S'IYAAMA S'ALLI A'LAA MUH'AMMADIN WA AALI MUHAMMAD WARZUQNEE H'AJJA BAYTIKAL H'ARAAM FEE A'AMEE HAAD'AA WA FEE KULLI A'AM WAGHFIR LEE TILKAD'D'UNOOBAL I'Z'AAM FA-INNAHOO LAA YAGHFIRUHAA GHAYRUKA YAA RAH'MAAN YAA A'LLAAM

O Allah, the Lord, (this is) the month of Ramazan, in it Thou revealed the Holy Quran, and in it made obligatory "fasting" upon Thy servants, send blessings on Muhammad and on the children of Muhammad, and provide us with the means to go to Thy Sacred House for "Hajj" this year and every year; and in this month forgive my grave sins, verily, other than Thee, no one can liberate (me) from its consequences, O Beneficent, O Omniscient.

Recite Dua-e-Iftitaah.