Is there a free web site were i can find out who I'm related to?

I love history and I'd like to know who my ancestors are. my parents never say anything about their grandparents I don't even know their names. I only know my moms maiden name is winans and my dads last name is grimes. I don't know where to start.? I've tried ancestry.com but they want money and I don't have a job I'm a stay at home mom and my husband thinks its a waste of money. I really want to find out who I'm related to. Thanks for helping.