Once you know what you have to work with START SMALL. Find the agent that is willing to show you homes that you have a good chance of turning over, not just homes that are vacant. There are fabulous deals on bank owned and HUDs, you have to be patient to find them and act quickly when you do (otherwise you will lose out to other bidders/investors).
Once your get your property I cannot stress enough the need to keep it small and stay focused. I have run into many an investor that got carried away with upgrades to the point where they need to recoup so much money the home ends up priced way above a sellable range.
Hope that helps.