Below is a link produced by the National Association of Home Builders (NAHB) which I believe is one of the most detailed sites for reference of the $8,000 Federal Housing Tax Credit, along with Questions & Answers. I found it very helpful and think you will too!

http://www.federalhousingtaxcredit.com/

Federal Home Buyer Tax Credits

Who is eligible?
First-time home buyers, are buyers who have not owned a principal residence during the three-year period prior to the purchase, may be eligible for a tax credit of 10% of the home purchase price, up to a maximum of $8,000.

Existing home owners who have been residing in their principal residence for five consecutive years out of the last eight and are purchasing a home to be their principal residence, may be eligible for a tax credit of 10% of the home purchase price, up to a maximum of $6,500.

All U.S. citizens who file taxes are eligible to participate in the program.

Income Limits

Home buyers who file as single or head-of-household taxpayers can claim the full credit ($8,000 for first-time buyers and $6,500 for repeat buyers) if their modified adjusted gross income (MAGI) is less than $125,000.

For married couples filing a joint return, the combined income limit is $225,000.

Single or head-of-household taxpayers who earn between $125,000 and $145,000, and married couples who earn between $225,000 and $245,000 are eligible to receive a partial credit.

The credit is not available for single taxpayers whose MAGI is greater than $145,000 and married couples with a MAGI that exceeds $245,000.

Time Frames
The eligibility period for the tax credit is for homes purchased after Nov. 6, 2009, and before May 1, 2010. However, home purchases subject to a binding sales contract signed by April 30, 2010, will qualify for the tax credit provided closing occurs prior to July 1, 2010.

Types of homes that qualify

All homes with a purchase price of less than $800,000 qualify, including newly-constructed or resale, and single-family detached, townhomes or condominiums, provided that the home will be used as their principal residence. Vacation home and rental property purchases do NOT qualify.

Tax Credit is Refundable

A refundable credit means that if the amount of income taxes you owe is less than the credit amount you qualify for, the government will send you a check for the difference.

All qualified home buyers can take the tax credit on their 2009 or 2010 income tax return.

Payback Provisions

The tax credit is a true credit. It does not have to be repaid unless the home owner sells or stops using the home as their principal residence within three years after the purchase.

Fact to consider when using the tax credit

Following are key points that prospective home buyers should be aware of when considering a home purchase under the tax credit program.

A tax credit of up to $8,000 is available for first-time home buyers purchasing on or after January 1, 2009 and on or before April 30, 2009. In cases where a binding sales contract is signed by April 30, 2010, a home purchase completed by June 30, 2010 will qualify.

A tax credit of up to $6,500 is available for repeat home buyers who have owned a home for five consecutive years out of the prior eight years. The repeat home buyer tax credit applies to houses sold after November 6, 2009 and on or before April 30, 2010. In cases where a binding sales contract is signed by April 30, 2010, a home purchase completed by June 30, 2010 will qualify.

Income limits of $125,000 for individuals and $225,000 for married couples filing jointly apply to all sales occurring after Nov. 6, 2009.

The income limits for sales occurring on or after January 1, 2009 and on or before November 6, 2009 are $75,000 for individual taxpayers and $150,000 for married couples filing jointly.

Homes priced above $800,000 are not eligible for either the first-time home buyer tax credit or the repeat home buyer tax credit.

Expanded tax credit benefits apply to members of the military, the foreign service and the intelligence community.
Home purchases in 2010 may be claimed on an amended 2009 income tax return.
Persons who are claimed as dependents by a taxpayer or who are under age 18 do not qualify for a tax credit.

Home purchases from relatives of the taxpayer or the taxpayer’s spouse do not qualify for the tax credit. The IRS defines relatives as ancestors (parent, grandparent, etc.), lineal descendants (child, grandchildren, etc.) and spouses.

Married couples are not eligible to claim the first-time home buyer tax credit if either spouse has previously owned a home. They may, however, qualify for the repeat home buyer tax credit.

Neither the first-time home buyer tax credit nor the repeat home buyer tax credit have to be repaid unless the home is sold or ceases to be used as the buyer’s principal residence within three years after the initial purchase.

Taxpayers must submit a copy of the HUD-1 settlement statement and IRS Form 5405 to claim either the first-time home buyer tax credit or the repeat home buyer tax credit