Matt,
I think I'm missing something. You said you've done the seminars, etc. Pretty much every REI class includes at least a basic discussion of marketing. Did your classes cover marketing? If so, like Jesus said, that's where you should start, because you've got to get sellers calling you. If we've misunderstood, please give us more detail on what you meant in your question about where to start.
At any rate, welcome to the to DFW REI Club! If you want to chat, please feel free to give me a call at 817-300-1132.
Thanks,
Robin