@Megan Davis Jeff is right, there is no magic bullet that gets you leads. Mailers is a sure fire way to find deals in a passive manor. I am a little partial to driving for dollars for obvious reasons. But if you are looking for a more active way to find deals, I find that getting into the field and viewing other peoples deals is a great place to start. I like to call off of wholesale signs and start looking at other peoples deals so I can potentially sell their house and use that as a baseline for what I should look for. I can get a sense of what things are selling for or "where I need to be" in my pricing to move something very quickly. From their, I turn to MLS. I know some people will hurl grenades my way for even mentioning finding good deals on the MLS, but they are their. Obviously, you probably are not going to go pick one off that is newly on the market and get a honey of a deal, but you can certainly work an area and spot some deals that could be negotiated down to a buy.
If I really want to dive into the world of research, I will start perusing the obituary section of the news paper and see where that takes me. I would encourage you to use caution in how you approach the situation, the loss of someone is never an easy situation, but sometimes it does cause unwanted problems like inherited real estate.