First things first, make sure you have enough people in the desired market -that is the most important. Yes, I know deals can be found everywhere, but having a large market will make everything so much easier. A nice number is at least 200,000.
Second, find out what is being bought. If you are a Real Estate Agent or an investor who does fix-and-flips and targets retail buyers, its easy. Visit Zillow.com (my favorite) and find out what type of property is selling most and for how much. If you are a Wholesaler, it's a bit more difficult. Work with a Real Estate Agent and see if they can search the MLS for recent cash transactions in your area -this will bring up every home that has been purchased with cash in your area recently; those are usually investors.
Third, find the crime areas. NO ONE purposely buys in a bad neighborhood. Investors hate them and so do retail buyers. If you visit trulia.com and click the "Local info" option that shows in the "Local info" drop box you will be able to check out the crime map for your desired area.
Fourth, now that you've got an idea of what's around the city, call other investors and wholesalers in the area and visit the REI groups -if you can- to find out what and where they LIKE to buy. You already have a good idea, but gleaning information from the investors in that area is ALWAYS a plus, in addition, you get the chance to grow a relationship with them and -possibly- putting them on your buyers list.
Fifth, use the information you've gathered to find the best areas to market in. With this, you should be able to target motivated sellers in "hot" areas. If you do this correctly, when it comes time to selling your house, you will have a property that buyers will be scrambling to buy.
Hope this helps a bit, I am in a small market, so I do all of my marketing online in areas that are pretty far away. I usually miss out on the REI club meetings because of this and that is a major setback for me and my business.