If you'd like general information and tutorials on using library resources, check out this Library 101 guide: https://guides.library.duke.edu/library101
I include a Library 101 video on finding articles on the Article and Data Sources tab of this Bio89 guide, and the Citing Sources tab redirects to Library 101 as well.
Getting the Full-Text of Articles
Many databases only provide abstracts and not the full-text of articles. Look for the Get It @ Duke button near an article citation and click on it to see whether the library provides online access. Or, install a browser extension like LibKey Nomad or the Library Access Button for easy access (see here).
Off-Campus Access to E-Resources
Most online library databases and journals can be accessed off-campus via proxy server. You will need to authenticate with your NetID and password. Details, including VPN and other options, are here.
If the library doesn't provide access to a particular article or book, you can still get it through Interlibrary Request. For each article or book, fill out this form.
Don't forget to search the library catalog for books like these...