Overseas Research
Go to the Family Search Research Wiki at https://www.familysearch.org/wiki/en/Main_Page
Enter the location in the search box. Select from the choices that appear, such as [location] genealogy, [location] Societies and so on.
Selecting Societies brings up a list. Some have websites and some are likely to be in the United States.
The web sites will sometimes have English-language versions
Go to the Search section of Ancestry to view the collections for that particular area. Example: Bavaria
Do an online search for something like “[location] genealogy services.” Somewhere in the list will be links to professional genealogist who cover your desired locations.
Check the Association of Professional Genealogists for someone living in your research location.
Where'd they come from?
How to find towns where your ancestors lived in Europe, Great Britain and Scotland? The key is border-crossing records of any type! Ideas: Use the Family Search research wiki to find out what records are available for the locations of interest. Census records in the USA point to overseas origins. Passenger records/ immigration records give a great deal of detail. Naturalization records have specific information. Excellent records exist for the UK and Ireland.