I just read your house post, and I figured I'd be jumping in early. H and I are in the process of buying a home right now in rural Nebraska using the USDA loan. Our loan is 100% financing, plus there is a USDA grant that covers $4k of the closing costs. Prices here I'm sure are much cheaper than they are in Oregon, but we are buying a home listed at 95,500 for 92,000. Because the seller doesn't have to pay closing costs, they are installing a new furnace, AC, and water heater all at their expense, plus anything else that comes up in the inspection. Our closing costs will only be about $800 out of pocket.
My advice would be to find a Realtor that has experience with the USDA loan process. If you are using someone that's used to selling homes in the city, they might not know all the specifics of that type of loan. I would look for someone who deals specifically in rural areas. We had no idea that the USDA loan even existed until we met with our Realtor and he walked us through the process. Our bank specializes in this type of mortgage as well, so our loan officer had lots of info for us.
I'm not sure if this is always true, but we don't actually pay our realtor anything. He gets paid on commission from the sellers, not the buyers.