Just married, how do I change my last name to my husbands'?

My husband and I got married back in July.We got married at the courthouse but I don't remember them ever asking me if I wanted to keep my maiden name or change it to my husbands.I called back the Courthouse and they said I need to go to the DMV and the Social Security Office.My question is I want to know EXACTLY what I need to bring to BOTH offices in order to change my name and the steps I need to take to make it official.How ever can give me the BEST and most Thorough answer ,while getting to the point,will get picked as "Best Answer".Thank you so much for your help!