Go to your county sheriff's web site or physical office. Find out when the sales are and what properties are available. Find out if the place looks ok from the outside. Narrow down what your interested in. Find out if additional liens are on the property through public records. Go to the sale and bid.
Rules differ from county to county. Generally, you need 10% up front with cash, cashier's checks or personnal check. And you typically have 10 days to pay the balance or lose your deposit.