Finding Documentation
From Italian Dual Citizenship Wiki
Universal Resources
The following websites can be used for help finding documentation. The subreddits linked are great for asking questions as well. There are state specific guides below, some are in the process of being updated.
https://www.reddit.com/r/juresanguinis/
https://www.reddit.com/r/Genealogy/
https://www.ancestry.com/ (has a free 14 day trial that gives you access to documents. You can still log in after the trial without a membership for reference and build the same tree with the same resources on FamilySearch).
U.S. Census records are useful for helping to determine eligibility, but are not records that the consulate will accept.
New York
New York State (Outside of New York City)
Getting Court Orders for Documentation
In New York State, you will need a court order for any marriage, birth, and death records where you are not the spouse, adult child (in some cases), or parent (in some cases) of the ancestor.
Costs
There are fees to order all records listed below. Documents can be requested either by mail-in or online; mail-in is cheaper at $30 per record, but may take longer. Online is $53 per record ($45 plus an $8 processing fee), and secure shipping with tracking adds another $15-$17.50 to the total, but you can have the documents shipped for free through regular mail with no tracking or insurance.
Birth Certificates
You can order birth certificates if it is your own or your child's (where your name is listed as a parent). All others require a court order. It is worth asking any living relatives in the line to order their own to send to you.
Birth Certificates can be ordered through the NYS Department of Health. They need to be "long form" birth certificates in order to be accepted by the Italian consulate. Most original copies are not long form, so you may need to order a long form version of your own birth certificate, in addition to ancestor birth certificates (through a court order).
Difference between long form and short form birth certificates: https://www.usbirthcertificates.com/articles/birth-certificates-long-form-vs-short-form
Order certificates here: https://www.health.ny.gov/vital_records/birth.htm.
Marriage Certificates
You can order marriage certificates if it is your own certificate. All others need a court order. It may be worth asking living relatives to order their own on your behalf.
Marriage certificates need to be "long form". Your original marriage certificate may be short form and would not be adequate.
The marriage certificate needs to be ordered from the county that the marriage license was purchased in, which may be different from where the marriage took place.
When ordering online through VitalChek (the site that the "order online" link brings you to from the Dept. of Health site), if a name change occurred as result of the marriage, enter the maiden/former last name on the "Certificate Details" page that asks for the names of both spouses.
Order here: https://www.health.ny.gov/vital_records/marriage.htm
Death Certificates
You can order a death certificate if you are the spouse, parent, child or sibling of the deceased. All others need a court order. It may be worth asking living relatives to order one on your behalf.
Death Certificates need to be "long form". Original issued copies may be "short form", so you may need to request a long form certificate even if you have an original copy.
Order here: https://www.health.ny.gov/vital_records/death.htm
Pennsylvania
Lawrence County
A good place to start to do a search if your family was in Lawrence county, including New Castle, PA. You can send requests to the Prothonotary for $12 a request:
https://lawrencecountypa.gov/gov/prothonotary-lawrence_county/genealogical-searches/
FamilySearch.org
More and more images from the consulate's books are showing up online. If you know the consulate, ancestor's name(s) and the approximate year, you can try to find birth, marriage and death records pretty easy.
After you create/log in to your familysearch.org account, you can check out this example from Sant'Aresenio, Salerno:
Catholic Diocese of Pittsburgh
You can do searches in the Catholic Church in the Pittsburgh area