Al-Malahim wa al-Fitan

From what they mentioned in Kitab al-fitan of Na'im b Hammad al-Khuza'i who reports from the Shaikhs (teachers) of Bukhari and al-Rumadi and other scholars of hadith. They said: Na'im told us that  al-Walid and Rushdin told him while reporting on the authority of Abu Lahi'ah who is reporting from Abu Qubail from Abu Ruman from Ali (as) that he said: When a caller shall call from the heavens that Truth is with the family of Muhammad (sa), at that time the Mahdi become the main topic of discussion on people's mouths while they rejoice and they shall not have any other topic of discuss other than him.

Bihar al-Anwar:
Kitab Tarikh Qum.

It has been reported from al-Sadiq (as) through a number of chains that he mentioned Kufah saying: "Kufah shall be devoid of believers and knowledge shall sneak out of it just as a snake sneak out of its hole. Eventually knowledge shall appear at a place known as Qum. It shall become the mine of knowledge and virtue so much that even the young girls shall be veiled (from the eyes of strange men). This will happen towards the appearance of the Mahdi. Allah shal make Qum and its people the representatives of truth and authority. Had it not been for that the earth would swallow its people and no
hujjah would be left on earth. Knowledge shall gush from it (Qum) to the rest of the world; in the East and West and Allah authority will be completed on his creation so much that there shall be no one upon the face of this earth to whome the message of Islam and the knowledge has not reached him. At that moment the Mahdi shall appear and he will become the reason of Allah's wrath and anger because Allah will not take a people to account until they reject the Truth.

Al-Burhan fi 'Alamat al-Mahdi:

The proof regarding the sign of the Mahdi of the end of time: Daraqutni mentioned a hadith in his Sunan on the authority of Muhammad b Ali that he said: Our Mahdi shall have two signs which have never happened since Allah created the earth and the heavens. The moon shall eclipse on the first night of Ramadan and the sun shall eclipse in the middle of the same year  and this has never happened since Allah created the heaven and earth.

Sunan Ibn Majah (vol.2)
The Chapters of Fitan:
The Chapter of the Signs:

Ali b Muhammad told us that Waqi' told him that Sufyan told him while reporting from Furat al-Qazzaz from 'Amir b Wathilah Abu Tufail al-Kanani from Hudhaifah b Usaid Abu Sarihah that he said: The Prophet appeared from Arafat while we were discussing the events of the end of time and said: The final hour shall not approach until after ten signs: The rise of the sun from the West, the Dajjal, the smoke, the beast, Gog and Magog, the return of Jesus the son of Mary (as), three eclipses; one in the East, one in the West, and one in the Arabian peninsular, etc. Abu Dawud (al-Sijistani) reported in his Sunan (Sunan Abu Dawud also known as "Risalat Abu Dawud ila Ahl Makkah") in the chapter of the signs of hour in the book of battles, from volume 2 with his own chain from Hudhaifah and others. Muslim (Muslim b al-Hajjaj al-Qushairi) also reported it in his Sahih (Jami' al-Sahih) in Kitab al-fitan wa ashrat al-sa'ah in the chapter of the signs before judgement day.