Download the "Application for Certified Copy of Birth Certificate" form from the website for the Office of Vital Records of the California Department of Public Health (see Resources).
Print that document.
Choose which type of birth certificate you want to obtain ("Certified Copy" or "Certified Informational Copy"), verify that you can legally obtain this particular birth certificate, write in your personal information (such as name, address, phone number) and write in the information that is found on the birth certificate (such as the names of both parents and date of birth).
Take the blank sworn statement (the final page of the application) to a public notary if you are applying for a certified copy of a California birth certificate. You must have a notarized sworn statement in order to obtain a certified copy of a California birth certificate.
Fill out the sworn statement in front of the notary and have the document notarized.
Make out a check or money order made payable to "Office of Vital Records." The fee for obtaining either a certified copy or a certified informational copy is $14 per document. For example, if you wish to obtain three copies of a birth certificate, make out a check or money order for $42.
Mail the application, notarized sworn statement (if applying for a certified copy of a birth certificate) and check or money order to
California Office of Vital Records
MS 5103
P.O. Box 997410
Sacramento, CA 95899-7410