Step one is to find out if the house is currently priced right. For many experienced short sale agents, when they first put a home on the market, they might price it competitive to other non-short sale homes. Typically the home won't sell right away and they may start to do a series of price drops. Lenders won't approve a short sale if the price is too low or the offer came in too soon way below the list price.
If you want to be successful, you need a great agent in your court. An experienced buyer's agent knows the in's & out's of getting short sale offer signed by the seller and approved by the bank. I encourage you to work with an experienced buyer's agent who can do the research and help you get the house you want at a great price.
One last thought, short sales can take weeks or even several months of uncertainty before they may get approved. Don't go down this road unless you have the time and patience. You won't like it.