How to petition/file for a child living outside the United States?

I, a US Citizen, married my wife, Romanian, while she was visiting the United States with on a tourist visa. I applied for her adjustment status (filed all the required forms). She has a 9 yr old son living in Romania that we want to bring here to live. The USCIS website shows that I have to file Form I-130 for the child. But what happens after I file it? Do we have to visit the US Embassy or consulate in Romania for the process? Does the child receive documents to travel to the United States? I can't find more information on the website about the process. Does anyone know? Any information is greatly appreciated!!