Finding Positive cashflow properties in the DC metropolitan area

[Charles Dean szollosy]

Please does anyone have tips on how to choose an area in which to start looking for a positive cashflow SFH or town house to purchase in the DMV? My pre-approved principal is $315,000, down payment is is approx $20,000 including fees and APR is 3.2%. Any advice will be greatly appreciated. Also how much cash flow is typical for this area considering my budget. Thanks!