Fasting Mondays and Thursdays:
Abu Hurairah reported that the most the Prophet would fast would be Monday and Thursday. He was asked about that and he said: “The actions are presented on every Monday and Thursday. Allah forgives every Muslim or every believer, except for those who are boycotting each other. He says [about them]: 'Leave them.' " (Related by Ahmad with an Authentic chain.) It is recorded in Sahih Muslim that the Prophet, peace and blessings be upon him, when asked about fasting on Monday, said: “That is the day on which I was born and the day on which I received revelations.”
http://www.islamonline.net/English/R...ticle_13.shtml
i searched and found this hope it is beneficial and also some other hadiths abt fasting:
"Every action of the son of Adam is
given manifold reward, each good deed receiving ten
times its like, up to seven hundred times. Allah the
Most High said, 'Except for fasting, for it is for Me
and I will give recompense for it, he leaves off his
desires and his food for Me.' for the fasting person
there are two times of joy; a time when he breaks his
fast and a time of joy when he meets his Lord, and the
smell coming from the mouth of the fasting person is
better with Allah than the smell of musk."
[al-Bukhaaree]
Sahl ibn Sa' said that the Prophet (s.a.w.)
said: "Indeed there is a gate of Paradise called
ar-Rayyaan. On the day of Resurrection those who fast
will enter through it; no one enters it except for
them, and when they have entered, it is closed so that
no one enters it, so when the last of them enters it,
it is closed, and whoever enters it drinks, and
whoever drinks never becomes thirsty." [Ibn Khuzaimah,
Saheeh].
"Fasting is a
shield with which a servant protects himself from the
Fire." [Ahmad, Saheeh] and his saying (saws) "No
servant fasts on a day in the path of Allah except
that Allah removes the hellfire seventy years further
from his face." [related by the group except for Abu
Dawood]