In general, to find out who owns the house, you can call the city or county and they will tell you as it is a public record. Finding out if/when it is going up for sale is more challenging. If it bank owned, once you find out who the owner is, you can check the bank's web site. This might tell you who the listing agent will be.
Or you can get a buyers agent hand she or he will do the leg work for you.
Good luck, Lori!