I'm including some links to get your started. However, please feel free to contact the reference desk again for additional assistance and include a specific search you are working on and/or the database you are working with. This will help us provide more specific suggestions for you.
Tip: when prompted for a username/password when using the University Libraries online resources, use your USD email/password login information.
This link leads to a Research (LibGuide) Guide related to using Archives and Speical Collections resources:http://libguides.usd.edu/ASC-Collections?hs=a. There are also tutorials on database searching available from the University Libraries homepage--click Research Tools from the menu on the left side of the page.
For expert assistance related to Archives, the University Library Archivist, speccoll@usd.edu or 605-677-8867.