Hi. You can get MLS access yourself; not full access, but access. Some local RE agents have very good websites that can help you -- www.franklymls.com or Listingbook (with RE invitation access) are pretty good. So are other sites like Zillow and Redfin. That should help you in some way.
Be sure to check your locale about bandit signs...you don't want to get into hot water. I have seen them around Stafford, but Walmart isn't too kind about them being on their property. Be careful in Woodbridge - they aren't all for signs either.
It's a good start to check where the high traffic areas are. I know traffic in murder in our area, but take a weekday trip to Stafford and FXBG before the afternoon rush. Tour the major roadways like Rt 1, 610, 630, & 17...you should immediately notice what I am talking about. If not; I'll be more than happy to show you around!!!
As for me; I haven't done any signs yet. I am still new at this so I haven't got up the courage. Plus I see bandit signs for wholesaling all over the place...competition is steep down here!