Sheriff's Sales are really for fairly sophisticated investors. You will be on your own, and really need good knowledge of property values. Also, there is a two year redemption period during which the former owner can redeem the property, albeit they do have to pay a fairly stiff interest rate.
You do not have to bid sight unseen. A notice listing the properties coming up for auction is posted at the county court house, and you can often call to get the list. Some counties also provide the info online.
If you are interested in buying a home, you are better off finding a REALTOR to help you find a decent foreclosure, better off yet if you find a short sale, and significant numbers of sellers are selling at foreclosure level prices these days. Short sales are usually in better condition than foreclosed properties, and sell for about the same. The advantage of buying a drastically reduced home is that you may just be able to get an even better deal, including seller contributions to your closing costs--plus a seller's disclosure of property condition, which you will not get on a foreclosure.
Sarah is incorrect in her saying you only need 10% down. Maybe that is how they operate in Kansas, but in TX you can only buy "all cash" via cashier's checks. Also, you pay for the property on the same day as the auction. It will take a few days for the paperwork to process and you'll recieve the Title shortly thereafter.
If you are a winning bidder but don't have the cash then you can be disallowed from bidding until you get back into good standing.
I suggest to go the auction and watch how it works and talk to the participants and get their insight. Then come back the next month if you find a property you might want to bid to purchase.