Once you have completed the paperwork, you can mail it or drop it off in person. The date of birth and physical description of the noncustodial parent.
Photographs are very helpful.
The social security number of the noncustodial parent. The birth certificate for each dependent child. A decree of divorce or legal separation agreement between you and the noncustodial parent, if applicable. The name and address of friends or relatives of the noncustodial parent. Any and all information relating to income and other assets of the noncustodial parent.