The most commonly used citation style in historical scholarship is Chicago, notes and bibliography. Check out our Citation Guide for other styles, and more in-depth information about Chicago. For help with citing primary sources, see this resource from the Library of Congress.
Wikipedia has a list of newspapers that are available online, sorted by country. Keep in mind that this list could be out of date and/or incomplete.
A handful of links to local resources and organizations here in the Twin Cities to help kick-start your research process.