If you are recently married and would like to change your maiden name, you don't need to file a petition with the court. Instead, your marriage certificate serves as your "proof," and you just need to update the Department of Motor Vehicles, banks, credit cards, etc.
First, you need certified copies of your marriage certificate. A photocopy will not be sufficient. Call the office where your marriage certificate was issued, and ask to get about three certified copies. These will typically have a raised seal on them.
Next, you should use the certified copy of your marriage certificate as proof to change your name with the following government agencies:
Social Security Administration You will need to complete Form SS-5 and send it by mail (or deliver it in person) to the Social Security Administration. There is no cost. You can download the form, as well as instructions on how to complete it, by following this link: http://www.ssa.gov/online/ss-5.pdf
The Social Security Administration will also notify the Internal Revenue Service on your behalf, so you do not need to file anything directly with the IRS.
Department of Motor Vehicles Bring a certified copy of your marriage certificate to the nearest Department of Motor Vehicles office, and let them know that you've changed your name. Oftentimes, you will need to personally appear at the office, so make an appointment if possible. You can change the name on your driver's license, as well as the title to any automobile that you own.
Passport If your passport was issued one year or less from the date of your marriage, then you will need to complete Form DS-5504 and send it to the US Passport Agency, along with two color photos, a certified copy of your marriage certificate and your old passport: http://travel.state.gov/passport/forms/ds5504/ds5504_2663.html
Other Institutions Once you have your new social security card and driver's license, changing your name with other institutions should be fairly straightforward. Some will want proof of marriage, others may want a copy of your new social security card or driver's license. You should contact them individually to see what they require:
Banks and other financial institutions
Employer (payroll and retirement plans)
Mortgages / Deeds
State tax authority
The above process is the same if you would like to use a hyphenated last name (with both your maiden name and husband's last name). However, you will need a formal name change petition, filed with the court, if the husband would like to change his name, or if you would like a new last name which is completely different from either your maiden name or the husband's last name.