Here is the link for the official U.S. Department of State's website of the Green Card Lottery (ELECTRONIC DIVERSITY VISA LOTTERY): http://www.dvlottery.state.gov/
The registration period for the Green Card Lottery normally runs from October 2, through November 30.
DV Entrant Status Check is now available on the above mentioned website - you can check the result if you won Green Card.
More information about the Green Card Lottery programme: http://en.wikipedia.org/wiki/Diversity_Immigrant_Visa
