Where Do You Think I Can find goverment grant to help me buy a home?

I suggest you check out non profits, who are the recipients of most housing grants. Check out Habitat for Humanity.
,
Also visit the Nehemiah Corp as they have a downpayment assistance program for qualified lenders http://www.getdownpayment.com/
,
The Housing and Urban Development in their Grants Available page makes it clear that they do not provide grants to individuals -- hence no grants for a person to buy a home http://www.hud.gov/grants/index.cfm
,
"While HUD does not offer direct grants or loans to individuals, we do work through local governments and non-profit organizations to make financial assistance and counseling available."
,
You can go to the Catalog of Federal Domestic Assistance (CFDA) http://www.cfda.gov and Grants.gov http://www.grants.gov - these are two FREE sites created by the federal government to provide transparency and information on grants. Browse through the listings and see if you can find any grant that would support your purposes.
,
Even if you buy books on "how to get grants" or list that supposedly has information on grants -- all of them are mere rehash of what CFDA has, albeit packaged differently.
,
Note though that these grants generally support non-profit organizations, intermediary lending institutions, and state and local governments. Most of the federal grants are given to specific target groups with specific requirements (e.g. minority business owners involved in transportation related contracts emanating from DOT - Grant#20.905 Disadvantaged Business Enterprises Short Term Lending Program. Individuals especially for personal purposes are not eligible for federal grants.
,
Grants are also often given to non profit groups or organizations involved in training or other similar activities (grant 59.043 Women's Business Ownership Assistance that are given to those who will create women's business center that will train women entrepreneurs.