I found a random unlisted house. Now what?

[Stephanie DeLeo]

Hello!  Driving around I spotted a house in a decent neighborhood that had a fat FOR SALE sign in the front yard and a phone number but it's not a broker sign.  The house is not listed online anywhere.  I checked public records and public tax records and taxes are up to date, so it doesn't appear to be a foreclosure/delinquent situation.  I want to call the number and ask about it but I am new to this - I feel I have only one chance. 

What questions do I ask in this first conversation to make me sound knowledgeable and seriously interested and that will also put me in an upper-hand negotiating situation?  What should I NOT say?  This home might be out of my price range but I want to find out as much as possible without showing all of my cards.  This could be a great rental property.  Thanks for any help!