There is a site called US Treasury Auctions at http://www.treas.gov/auctions/ that may be of assistance to you.
It is a good start, but nothing beats viewing the Lis Pendens auctions within a particular area and doing the foot work prior to an auction scenario. The key is to engage the home owner in a win-win scenario, so it is vital that you are able to find out what their particular scenario is and present to them a few options specifically detailed on helping them in their current needs.
Creative financing option should be a portion of your presentation. You may find that there are numerous people doing the exact same thing you are and that the person is avoiding all phone calls and mailings. Focus on personal contact and having an intimate “I am here to help you” approach.