My son has my maiden name, the father wants him to have his last name he goes to court on Dec 4th 2009 and I'm wondering do I need to be in court as well for him to change our sons' name. He is not on the birth certificate

Yes you should be there unless you don't object to his name going by the fathers last name and not yours. Other then that if you want to keep yours also then you might want to ask that it be hyphened so both names can be included. If you don't show then you have no representation and it will be his way only.