Newbie at finding off market deals

[David Maldonado]

Hey BP community!

I decided to go give driving for dollars a try to hopefully land an off market deal. I managed to find a house that looks run down.  The backyard looks like a dump and the entire neighborhood can see it. Sits on a corner lot, front yard is hideous and when I knocked on the door, the door almost opened up. The owner wasn't home but managed to get information from the neighbors. They say the home is free and clear and the owner (obviously) doesn't maintain it. I plan on sending direct mail and from time to time pass by in hopes of him being home. How should I approach the owner if he decides to get in contact with me? 

Also anyone reccomend any books on finding off market deals?