some property listings will say so...its not an "easy" task to find...you will have better luck fnding places for rent and seeing if buying is a possibility...most seller want to sell...but in some cases may consider renting...talk to their agents.
If you find a lease to own house make sure you understand the contract first. If you want to lease now to improve your credit, it is a good idea to sit down with a lender to see what needs to be done and what the chances are for getting a mortgage next year or whenever you plan on buying.. Lenders are getting stricter.
The others have given you information about how to find properties. Good luck.