The National Council of State Housing Agencies website has links to state agencies that can help home buyers. This page at NCSHA has a drop down to find the agency for your state. Simply select your state and it will give you a pointer to your states agency.
It seems that every state has some sort of program to help first time buyers afford a home. The details of each states program differs but it seems that in general you have to be below an income threshold and the cost of the house has to be below a maximum. Generally it looks like the income limits are around median income levels so most people should be able to qualify as first time buyers.
For example I select Alabama (first on the list) and it points to the Alabama Housing Finance Authority website. I poke around there and find they have a Mortgage Credit Certificate program that gives you a tax credit for 20% of the interest of your mortgage. So with a $100k loan at 6% you'd get $1200 in tax credit annually. Thats $100 to help you towards the purchase of your home.
Some states have below market interest loans, help with closing costs or other benefits to help new home buyers. To see if your state has a program that could help you buy your first home check out the page at NCSHA.