Name Change

I have a 3 part question for you: 1. When my son was born I gave him my last name on his birth certificate. The father and I plan to get married and I would like to change my son's name to his father's last name. Does it make it easier or less expensive to change it before or after we get married? 2. I also want to know if I were to purchase the legal forms from this site (US Legal.com) what would be the simplest way to process those forms. 3. Does this process change the social security card and birth certificate? If not, what is involved with changing those documents?

I am a British citizen living with my husband who is American in Arkansas. Both of my children, aged 8 and 11, are British as my husband is there stepfather. Can we legally change their names to there stepfather's name. We have no contact with their birth father as he left when they were babies. I have no way of getting in contact with him.

Can I change my mothers name on my birth certificate to my step mothers name? I have never met my birth mother and have lived with my step mother since I was 2 and she is the only mother I have know. I am 18 years old and want to do this for myself.

The last name that I have been using since birth in school and everywhere else is the last name of my biological father. However recently found out that on my birth certificate it lists my last name as my mother's maiden name and no father. How do I change it as an adult because, I need to for college financing. Also since I do not use my mother's maiden name for anything, it is okay that I do not have any documents with that name?

Considering changing name in Oregon. I have an outstanding warrant in Maryland for a non felony possession from 2005. Wondering if this will be automatic denial of petion.