The holy Prophet(SAW):The world will not come to an end until a man from my family (ahl al-bayt), who will be called al-Mahdi, emerges to rule upon my community.(Bihar al-anwar,V51,P75)

Aa'mal and prayers of Eid-e-Ghadir

1. It is recommended to take bath early in the day for purification.
2. Observe fast on this day.
3. Recite Ziarat-e-Ameenullah and Ziarat-e-Mutliqah
4. Recite Dua-e-Nudba
5. Offer 2 rak'at prayer of Eid-e-Ghadir before mid-day. In each Rak'at after Surah Hamd recite Surah Tauheed 10 times, Surah Qadr 10 times and Ayat al-Kursi 10 times. This prayer is highly rewarding and whatever dua is asked from Allah (swt), inshallah, will be granted. It is recommended to recite this prayer closer to but before mid-day since that was the time when Prophet Muhammad (pbuh) announced the successorship and nomination of Imam Ali (as) as master of the faithful.

After the prayers go into prostration and recite "Shukran Lillah" 100 times and "Alhamd-o-lillah" 100 times. Imam Ja'far Sadiq (as) says that whoever does so will be like a person who accepted the Imamate and Caliphate of Imam Ali (as) and pledged allegiance at the Ghadir-e-Khum in front of Prophet Muhammad (pbuh). The person who performs this act will also be like those who will be with the Imam-e-Zamana (as) under his flag.
6. At the time of meeting with the brothers-in-faith say the following:
ALH'AMD U LILLAAHIL LAD'EE JA-A'LANAA MINAL MUTAMASSIKEENA BIWILAAYATI AMEERIL MOOMINEENA WAL A'IMMATI A'LAYHIMUS SALAAM
All praise is to Allah, who blessed us to be among those who cling and hold to the
"Wilayaat" (love, friendship and authority) of Ameer Al Momineen (as) and all the Imams, peace be on them all.
ALHAMD U LILLAAHIL LAD'EE AKRAMNAA BIHAAD'AL YAWME WA JA-A'LANAA MINAL MOOFINA BI-A'HDIHI ILAYNAA WA MEETHAAQIHIL LAD'EE ATHAQANAA BIHI MIN WILAAYATI WULAATI AMRIHI WAL QAWWAAMI BIQISTEHI WA LAM YAJ-A'LNAA MINAL JAAHIDEENA WAL MUKAD'D'IBEENA BIYAWMID DEEN.
Praise be to Allah who honored us with this day, and included us among those who have been given all that which was promised to them, and have been tied together with the bonds of contract to have full confidence in the authority of the guardians of the religious laws who established justice; and did not disgrace us to be among those who know better but deny the truth and treat the Day of Judgement as a false fable.
7. Recite 100 times:

ALH'AMD U LILLAAHIL LAD'EE JA-A'LA KAMAALA DEENIHI WA TAMAAMA NIA'-MATIHI BIWALAAYATI AMEERIL MOOMINEENA ALIY YIB NA ABEE T'AALIB A'LAYHIS SALAAM.
Praise be to Allah, who had perfected His religion and completed His favour with the establishment of Ali ibn Abi Talib's authority, peace be on him.