Read all Ahadith in the book on fasting by jami al tirmizi

Abu Hurairah narrated that : the Messenger of Allah said: On the first night of the month of Ramadan, the Shayatin are shackled, the jinns are restrained, the gates of the Fires are shut such that no gate among them would be opened. The gates of Paradise are opened such that no gate among them would be closed, and a caller calls: 'O seeker of the good; come near!' and 'O seeker of evil; stop! For there are those whom Allah frees from the Fire.' And that is every night.

Abu Hurairah narrated that : the Messenger of Allah said: Whoever fasts Ramadan and stands (in the night prayer) for it out of faith and seeking a reward (from Allah), he will be forgiven what preceded of his sins. Whoever stands (in the night prayer) on the Night of Al-Qadr out of faith and seeking a reward (from Allah), he will be forgiven what preceded of his sins.

Abu Hurairah narrated that : the Prophet said: Do not precede the month with a day nor with two days, unless that fast falls on a day that one of you would have (normally) fasted. Fast with its sighting and break fast with its sighting, and if it is cloudy, then count for thirty days, and then break (the fast).

Abu Hurairah narrated that : the Messenger of Allah said: Do no precede the month of Ramadan by fasting a day or two before it, unless it is the case of a man who normally performs some fast, then let him fast it.

Silah bin Zufar said: We were with Ammar bin Yasir when a roasted sheep was brought and he said: 'Eat.' Someone among the people said: 'I am fasting.' So Ammar said: 'Whoever fasts on a day in which there is doubt, then he has disobeyed Abul-Qasim (pbuh).

Abu Hurairah narrated that : the Messenger of Allah said: Count the (the appearances of) the crescent of Sha'ban for Ramadan.

Ibn Abbas narrated that : the Messenger of Allah said: Do not fast before Ramadan. Fast with its sighting, and break fast with its sighting, and if it is obscured from you, then complete thirty days.

Ibn Mas'ud said: What I fasted with the Prophet hat was twenty-nine (days), was more than what we fasted that was thirty.

Anas narrated: The Messenger of Allah vowed to stay away from his wives for a month, so he stayed in a loft for twenty-nine days. They said: 'O Messenger of Allah, your vow was for a month,' so he said: 'The month is twenty-nine (days).'

Ibn Abbas narrated: A Bedouin came to the Prophet and said: 'I have seen the crescent.' So he said: 'Do you testify that none has the right to be worshipped but Allah? Do you testify that Muhammad is the Messenger of Allah?' He said: 'Yes.' So he said: 'O Bilal! Announce to the people that they should fast tomorrow.'