Highlights that answer some of the questions already brought up:
# New homes only (never been occupied)
# Principal residence only (must live in home for 2 years following purchase)
# Credit is 5% of purchase price or $10,000 whichever is less
# Credit is applied over 3 years (max $3,333/year)
# The credit is not refundable (if you don’t owe $3,333 in taxes, you don’t get the difference back).