Help me understand

Can someone give me the Cliff’s notes version of short sale?

A friend (?) recently gave me a short book on short sales that has spawned many more questions than answers. I admit that my interest has been piqued, but the author seemed more interested in telling of his successes rather than provide the information needed to succeed in short sales. For instance, the author mentions that these sales can be made with minimal money out-of-pocket and without risking your own credit, but I fail to understand how a house can be purchased for resale without buying it outright (i.e. cash out of pocket) or by securing a loan (i.e. risking credit). Will someone please explain?

Also, the author mentioned $25,000 profits or better on each sale. Is that really realistic?

Thanks in advance for putting up with my ignorance in this area.


P.S. I also posted this same message in the beginners forum, but this seems like a more appropriate place. Sorry for the duplicate