I wrote in my blog different ways to find a Lease-to-Own property with and without the assistance of a Realtor. Here is the link:
As stated in earlier answers, it's key to find PROFESSIONALS who are familiar with the whole lease-to-own process. That includes a Real Estate Agent(if you choose to use one), a Real Estate Attorney, Credit Repair Specialist, and especially a Loan Officer/Mortgage Lender. If you work with the Lender from the beginning, it will make it much easier come closing time......AS WELL AS......making you look serious to a potential landlord/seller because you can tell them that you already have someone putting the steps in place for you to buy the seller's property.
The more "warm & fuzzy" you can make the landlord/seller by telling them how you are going to go about the whole process, the better. You want to educate yourself as much as possible so that if the seller has an objection, you can come right back with a positive to their negative or do a point-counterpoint discussion.
You should meet with a local bank or mortgage broker to find out how much time you will need to get a mortgage, what price range you qualoify for and what you will need to do to be able to get a mortgage in the future.