Homes for sale....legitimate or not?

I am perusing the NY Daily News classified ads and I am seeing plenty of homes for sales by owner with low down payments listed. Some say owner pays closing costs, etc. Some have an agent. These homes are in the borough of Queens in areas where many have experienced foreclosures. Now, are these legitimate. I am interested in home ownership. I have a high credit score, long term employment, and would love to stop renting ....the only problem is I don't have a huge down payment and my income is too high for those home ownership assistance programs. I do have something to put down....just not a lot. Anyhow, should I look at these offers or are they likely to be scams?