The Astronomical New Moon is on Thursday, 3 February 2011 at 0231 GMT. The crescent will only be visible in North America on this day.
According to the rulings of Ayatullah Sistani (based on The Theory of Differing Horizons), 1st Rabi ul Awwal 1432AH will be on Saturday, 5 February 2011.
For the Muqallideen of Marhum Ayatullah Khui, 1st Rabi ul Awwal will be on Friday, 4 February 2011.
Prayer on the first day of Islamic month (today): 2 Rak'at, 1st Rak'at: recite Sura Al Hamd and 30 times Sura Tawheed. 2nd Rak'at: recite Sura al Hamd and 30 times Sura Al Qadr, then give Sadaqa, you will get the safety for the whole month.