When it comes to spelling variations, be creative. Often clerks and government officials were unable to correctly record the names given them by unschooled immigrants not familiar with languages used in their port of entry. The surname was written down as the official heard it and the immigrant accepted that as the official American rendering of his name.
The National Genealogical Society, Washington, D.C. has a genealogical course available for national accreditation and sells both supplies and reprinted genealogies and other books.
Women were included under their husbands' naturalization until 1920. However, due to the Expatriation Act of 1907, a women lost her citizenship if she married a person from another country that had not already been naturalized.
Tax records, jury and militia records are indicators of a person's residence.
Use a good genealogical software package to maintain your records and your digital files.