Over 505,000 immediate relatives of U.S. citizens received a green card in 2019 (Statista). All non-asylum-seeking immigrants are processed by the citizenship and immigration services (USCIS).
The field offices of the federal agency perform the important duty of conducting in-person interviews and helping applicants with case-related information and communications. Anyone looking for this guidance may visit by making an appointment.
For the steps before the submission of your application, the USCIS site is the most helpful resource. Firstly, the site informs you about all the basic topics related to immigration such as green cards, citizenship, laws, and procedures. Secondly, the site has everything from forms available for online submission to submission fees and available payment methods.