I am unsure what steps you have already taken with the INS, on the assumption you have taken none, the following would be required (assuming you are a us citizen of course):- Form I-130 Petition for Alien Relative($110.00)
1. US citizens birth certificate
2. Certified copy of the adoption decree
3. The legal custody decree if you obtained custody of the child before adoption.
4. Statement showing the dates and places you have lived with the child, and proof that you lived with your child as a parent for at least two years.
You would also have to file I-485-Application to register permanent residence or adjusted status($160.00 for child under 14 years of age)
1. Form G-325A - Biographic Data(14 years or older)
2. Birth Certificate
3. Form I-693 Medical Examination Sheet
4. Two color photos taken within 30 days
5. I-864 Affidavit of Support
6. Evidence of inspection into the US(I-94)
This is a lengthy process and must be done before any naturalization, which can take between 2-5 years. Form N-643 Application for Certificate of Citizenship in behalf of an Adopted Child.$125.00.
Visit the INS website at
www.ins.usdoj.gov and read the section APPLICATION PROCEDURES: BRINGING CHILDREN TO LIVE IN THE UNITED STATES. You can call the National Customer Service Centre on 1 800 375 5283 and also request the appropriate forms on 1 800 870 3676. Hope this is of some help to you and good luck!